May 26, 04: "Your hair is what you do." It can tell if you
smoke, drink or take drugs and, growing at 0.3 to 0.5
millimeters a day, it keeps a record for months if not
years -- which is why some people taking illegal substances
shave their heads. Because different races have different
hair structures, analysis can also tell ethnic origin --
although it cannot reveal sex.
. . The average person has up to 150,000 hairs on the
head and a single strand can support 100 grams in weight. A
whole head of hair could therefore in theory support the weight of two elephants.
. . African hair grows more slowly and is more
fragile than European hair, but Asian hair grows the
fastest and has the greatest elasticity. Asian people also are ahead when it comes to keeping their hair, with Africans and Europeans more prone to balding.
May 26, 04: Chimpanzees are 98.7% identical to
humans. But the differences between the species are clearly
profound. Fujiyama's team compared chromosome 22 on three
different chimpanzees to its counterpart in humans,
chromosome 21. The team found just 1.44% of the DNA
was different at the level of single letters of genetic code.
. . While the genes and other DNA may look the same
in chimpanzees and humans, the proteins they eventually
code for can be very different. This supports what genetic
researchers have been saying lately -- that subtle changes
in the genetic code that reach far beyond the genes
themselves may be extremely important to biology. While
there may be no more than about 30,000 to 40,000 human
genes, there are more than 250,000 different proteins.
. . The researchers tried to calculate what the
genetic code of the original ancestor of both looked like,
6 million to 7 million years ago. It looked to them as if
the original ancestor of humans & chimps had a larger
genome, and each species pared it down differently as they evolved.
May 26, 04: Scientists have discovered bacteria living in
the toxic sediment beneath underground tanks that have
leaked radioactive waste at the Hanford nuclear
reservation, home to some of the most highly contaminated
soil in the world. The discovery eventually could help
researchers better understand how microorganisms can survive severe contaminants and how to use the bacteria to help clean up toxic environments.
May 26, 04: Blue roses could generate a lot of green. Two
researchers at Vanderbilt University took a gene from a
human liver and placed it into bacteria to better
understand how the body metabolizes drugs. "The bacteria
turned blue." If the process is perfected, it may be
possible to grow blue cotton for use in, what else, blue jeans.
May 25, 04: The gene called Frizzled6 must be important,
as it also affects the development of hair whorls in mice
and is found in creatures as primitive as fruit flies. It
may even affect the brain, they said.
. . To study the gene's importance, a team bred
genetically engineered mice that lacked Frizzled6 entirely
and also created mice that had various active versions of
the gene. Mice that lacked the gene were normal and healthy
but showed some unusual hair patterns such as whorls of
hair on their hind feet or the back of their heads.
. . The researchers noted that another team reported
in the journal Genetics last year that they had found a
link between hair whorls and whether people are left- or right-handed.
At the Earth's surface, sunlight provides about 100 watts
of power per square meter. But for every 100 watts of perfectly good sunlight, only
about 8 watts ends up as plant food. That means that your
typical backyard bush runs on only as much power as a
bicycle headlamp, even during the day.
. . As a typical adult, you need at least 2,000
Calories a day. Making the conversion to less arcane units,
that works out to about 100 watts of power, 24 hours a day.
But remember that if you got your energy through
photosynthesis, you would absorb only 8 watts for each
square meter of skin. Most of us have about 3 square meters
of epidermis, roughly half of which is in shade at any
given time (more, if you insist on wearing clothes). So
that's just over a dozen watts of daytime power, nearly 10
times less than our burn rate.
. . A hummingbird, an active animal, uses about 8
Calories per day, or about a half watt.
May 20, 04: A new study of purebred dogs says among those
closest to their wild wolf ancestors are the Siberian
Husky, Chinese Shar-pei and African Basenji. While dogs
have about 99% of their genes in common, a few very
distinct genetic differences separate them into some 400
breeds known worldwide.
. . Comparing dog genes to wolves, researchers found
that a group of ancient dog types split off first. Later
the majority of canines evolved into three other clusters
of dog variants -—hunters, herders and guard dogs-— largely
as a result of breeding programs developed over the last
several hundred years. A surprising 30% of genetic
differences among dogs can be accounted for by a few
hundred years of intense inbreeding --far more than the so-
called racial differences between humans. The number of
tiny genetic differences within a single species is not
seen in any other species.
. . Human families are too small and "its often
difficult to get samples from more than one or two
generations, whereas dog families are huge ... and you can
get DNA for two, three, four generations", she said. "That
gives you enormous statistical power for understanding the genetics."
. . In the process, scientists learned some
interesting things about dogs. For example, at least two
breeds long thought to be ancient, the Ibizan Hound and
Pharaoh Hound, were found not to be so old after all.
Because of their resemblance to dogs depicted on ancient
Egyptian tombs, they had been considered among the oldest
of breeds. However, their genes indicate they have been
developed in more recent times.
. . The study also showed five pairs of breeds with
very similar genetics: Alaskan Malamute and Siberian Husky,
Collie and Shetland Sheepdog, Greyhound and Whippet,
Bernese Mountain Dog and Greater Swiss Mountain Dog and
Bull Mastiff and Mastiff. [I still wanna know how much DNA is shared with Bears.]
May 14, 04: Lemurs are primates, as are monkeys, apes and
humans. Lemurs, once believed to be cute but basically
stupid, show startling intelligence when given a chance to
win treats by playing a computer game, U.S. researchers
reported. So far, it suggests primitive animals such as
lemurs need a good reason, such as a treat, to bother trying to count. Humans and monkeys, in contrast, will stretch their minds simply out of curiosity.
. . Unexpectedly, the lemurs could remember
sequences. For instance, they showed they could remember
the order of appearance of random images by touching them
in order when they reappeared as a group. "It shows that
the animal is actually learning some kind of strategy above
and beyond what they're learning about the individual pictures in a given set."
May 14, 04: Scientists at Montana State University in
Bozeman say they have discovered a heat-loving, acid-dwelling virus that could help provide a link to ancient life on Earth. The virus found in Yellowstone National Park
could help to understand a common ancestor that scientists
believe was present before life split into forms such as bacteria, heat-loving organisms and the building blocks that led to plants and animals.
. . They began hunting for heat-loving "thermophilic"
viruses in Yellowstone five years ago. In 2001, he and
others found several apparently unique viruses associated
with an organism living near Midway Geyser Basin where
temperatures ranged from 158 to 197 degrees Fahrenheit. "It
was basically something living in boiling acid", Rice said.
. . Although several new viruses were discovered, one
in particular caught their eye. After characterizing the
structure and genome of the virus, they found that its
protein shell was similar to a bacterial virus and an
animal virus. The similarity suggests to the scientists
that the three viruses may share a common ancestor that
predates the branching off of life forms more than 3 billion years ago.
. . For a long time, scientists classified all life
forms as plant or animal. That classification system
expanded as more life forms were discovered. Eventually, biologists divided life into five kingdoms —-plants, animals, bacteria, fungi and protists.
. . A more recent approach divides life into three
domains: bacteria, eukarya — which includes plants, fungi,
animals and others — and archaea, which means ancient.
. . Archaea, similar to bacteria, is likely the least
understood of the domains. Now that scientists know the Yellowstone virus's ancient
structure seems to span all three domains of life, scientists plan additional studies on its genes to figure out what they tell the virus to do.
. . Researchers said the virus and others found at Yellowstone will give researchers a hand in the search for life on other planets, including Mars.
May 15, 04: Lottery winners, trust-fund babies and others
who get their money without working for it do not get as
much satisfaction from their cash as those who earn it, a
study of the pleasure center in people's brains suggests.
. . Emory University researchers measured brain
activity in the striatum —-the part of the brain associated
with reward processing and pleasure-— in two groups of
volunteers. One group had to work to receive money while
playing a simple computer game; the other group was
rewarded without having to earn it.
. . The brains of those who had to work for their
money were more stimulated. "I don't think it ever evolved
to sit back and sit on the couch and have things fall in our laps."
Gravity's effect on trees' natural plumbing system would
make a tree taller than 426 feet impossible, according to the researchers.
New study: Lamnid sharks, which include mako and great
whites, have been separated on the evolutionary tree from
bony fishes, such as tuna, for over 400 million years. But
the muscles and tendons that enable them to swim so fast are remarkably similar.
May 14, 04: A remarkable "anti-freeze" protein prevents
the flounder from freezing up in northern polar oceans,
according to a study. Scientists have known for some 30
years that some fish species flourish in sub-freezing
waters thanks to plasma proteins, which cling to
microscopic ice splinters in the blood, stopping the
crystals from teaming up into larger structures that could damage cells.
. . The winter flounder has one of the best known of
these proteins, but the concentrations are so low that, in
theory, the flounder should turn into a fishy iceblock if
it ventured into waters colder than minus 1.5 Celsius.
. . The answer, according to Canadian scientists, is
a hitherto-unseen antifreeze protein that is very close to
the well-known Type 1 protein. In fact the two differ only
by a couple of amino acids, the building blocks of proteins.
May 13, 04: Migrating birds may get their internal compass
through a chemical reaction induced by the Earth's magnetic
compass rather than through magnetic material in their
beaks, as the conventional theory holds. The authors do not
rule out the possibility that magnetite could play a part
in navigation, but if so, this is probably as a sensor of
magnetic intensity rather than to locate where the field lies.
Apr 29, 04: More than three-quarters of a million years
ago, early humans gathered around a campfire near an
ancient lake in what is now Israel, making tools and
perhaps cooking food, in the earliest evidence yet found of
the use of fire in Europe or Asia. The new finding pushes
back the earliest evidence for control of fire by residents
of Asia or Europe by more than a quarter-million years.
. . Still unknown is exactly who these early people
were. The paper notes that residents of this site have been
assumed to be the now extinct Homo erectus or Homo
ergaster, but may also have been an archaic version of
modern humans, Homo sapiens.
. . There are earlier sites associating fire with
early humans in Africa, though some researchers believe the
evidence at those locations is ambiguous and natural fires cannot be ruled out.
Apr 29, 04: If you think your kids grow up fast, consider
this: A new study suggests that Neandertal children blazed
through adolescence and on average reached adulthood at age
15. The finding bolsters the view that Neandertals were a
unique species separate from modern humans, since the time
for humans to mature to adulthood grew longer over the course of their evolution, said paleontologist Fernando V. Ramirez Rozzi, who led the study.
. . If Neandertals and prehistoric Europeans could be
seen side by side some 35,000 years ago, "the Neandertals
would be bigger", Rozzi said. "Probably, human children of
about 5 years old would play with Neandertals that were 3 years old."
. . For more than 100,000 years, Neandertals roamed
across a vast region from Spain to southern Russia and
western Asia, overlapping with anatomically modern man for several thousand years.
. . Harvati said their quick maturation rate may have
been an adaptation to a harsh environment that decreased
their life span and made it important for youngsters to
reach sexual maturity quickly.
. . For his study, Rozzi spent about 18 months
examining growth patterns on the crowns of incisors and
canines from 55 individual Neandertals, comparing them with
corresponding patterns from early modern humans and
ancestors to both groups. Like rings on a tree, the time it
takes for a tooth to grow can be measured by counting
visible lines that form about every nine days on the enamel. On average, Rozzi found Neandertals developed teeth 15% faster than modern humans.
. . Erik Trinkaus of Washington University in St.
Louis said he's skeptical of the research. Human growth
varies widely within a population, he said. In fact,
Rozzi's study includes some Neandertal teeth that took as
long to develop as modern human teeth.
. . University of Illinois at Chicago anatomy
professor Jay Kelley said he's also concerned about making
conclusions based on what are essentially assumptions about Neandertal tooth growth.
The tallest tree on the planet, a giant redwood that soars
113 meters (370 feet) into the California sky, is still
growing. But scientists say it will not grow higher than
130 meters because the taller a tree gets, the more
difficult it is for water to get to the top.
Apr 21, 04: Japanese and Korean scientists have created a
fatherless mouse without using sperm in a reproductive feat
akin to the birth of Dolly the sheep, the world's first cloned mammal.
. . Bees, ants, aphids and some fish and reptiles
reproduce without having sex in a process called
parthenogenesis. But creating a living mammal from same-sex
parents was thought to be impossible.
. . Such a mammal is known as a parthenote. "The
parthenote developed to adulthood with the ability to
reproduce offspring. However, this was achieved with even
lower efficiency than the cloning process used to make
Dolly and therefore it is even more unacceptable and unsafe
to consider using this for humans."Only 0.6% of the
embryos Kono and his colleagues created survived.
Apr 22, 04: Using a method never applied to rock from
ancient Earth, researchers have found possible signs of
biological activity dating back nearly 3.5 billion years,
earlier than any other agreed-upon discovery of life on
this planet. The primordial life appears to have eaten
rocks to survive. The 3.5-billion-year-old tubes contain
carbon and traces of carbonates that could represent
organic material left behind by the primitive organisms.
. . Meanwhile, separate work is turning up intriguing
similar structures in Mars rocks found on Earth, though no
claims of life have yet been made with regard to this ongoing Martian investigation.
Apr 15, 04: Delicate shell beads dating back 75,000 years
are the latest evidence that humans started to act modern
almost as soon as they started to look modern, scientists
said. The findings nearly double the era of intellectually modern humans.
. . Found in a cave overlooking the Indian Ocean in
South Africa, the beads are made of tiny shells
deliberately pierced and strung. "We don't know exactly how
they were used, but we do know that in all instances where
beads are used in hunter-gatherer societies, the beads have
meaning. They are not merely decoration." The beads,
carried from a river about 12 miles away, are part of a
site where carved ochre dye sticks 77,000 years old were found two years ago.
. . The beads also suggest that intellectually modern
humans emerged in Africa rather than Europe. The oldest
fossil evidence for anatomically modern Homo sapiens is
about 130,000 years old and in Africa. But evidence of
human behavior has been harder to find.
. . The entrance was completely blocked for 70,000 years, until about 3,000 years ago, which is perhaps why its contents are so well preserved.
Apr 10, 04: Man tamed the cat around 9,500 years ago, more
than 5,000 years than previously thought, according to a
find of an ancient feline skeleton in Cyprus. Lying in a
shallow grave, buried just 40 centimeters opposite the
remains of a human aged about 30, the eight-month-old cat
may have been an honored member of that Stone Age household.
. . Until now, cats were first thought to have been
domesticated in ancient Egypt, by 1900 BC at the latest.
Cats were probably brought in from the wild in the very
early stages of agriculture, when humans stopped being
hunter-gathers and started farming. By storing grain, these early farmers would attract mice. Having a cat around would solve the rodent problem.
. . The domestication of dogs has a longer history,
no doubt because of the dog's use to hunt and guard for
humans. Dogs were associated with human burials at sites in
Israel dating back 14,500 years.
Apr 10, 04: The first tetrapods, or four-legged creatures,
migrated from the oceans onto land 365 million years ago.
Using DNA evidence, two Penn State University researchers
think they have answered a long-standing question among
scientists: Did snakes evolve from land-based lizards, or
did they come from the sea? They write that the genetic
evidence strongly suggests that snakes evolved from land-
dwelling lizards. It's a conclusion that confirms a general
trend in evolutionary biology, but bucks more than 100
years of thinking about reptiles.
. . Herpetologists, though, have been divided about
the origin of snakes. Some thought snakes evolved from land-
based lizards, losing their legs to better squeeze through
small holes and crevasses close to the ground. Others
thought aquatic lizards, such as mosasaurs, made a second
migration onto land as snakes.
. . Vidal and Hedges compared the DNA from 17 of the
25 known families of snakes to DNA from all 19 families of
lizards. They found snakes to be much more similar to land-
based lizards than they were to monitors, providing strong
evidence for a terrestrial evolution. They were looking at
genetic relatedness as opposed to anatomical structures.
They still haven't determined exactly where snakes began to
separate from the lizard family tree. "Now we need to
identify the closest relative of snakes. We don't have it
yet", Vidal said. "We can exclude monitors —-that's
statistically supported, strongly-— so we know their origin
is not marine. But all of the other lizard lineages are
terrestrial, so we have to find which one."
Apr 5, 04: Chimps and humans differ by only a tiny
percentage in their genetic make-up, but the reason why
they're in trees and we're not lies in who has the most
active genes, a leading scientist said. Svante Paabo, who
has been helping to decipher the genetic code of chimps,
said the key lies in the degree to which genes are used in each species.
. . Human and chimpanzee genomes differ by just 1.2
percent, he told the annual meeting in Berlin of the Human
Genome Organisation, yet around 10% of the genes are differently active.
. . Paabo said that as researchers made further
comparisons, other differences in how genes were stressed,
and therefore developed, would also be noticed. He said
scientists needed to unlock the genome of at least one more
primate in order to be able to identify key differences between them and humans.
Apr 1, 04: Fish did not grow legs to colonize the land as
previously thought, but to prop themselves up underwater
370 million years ago, according to US scientists. A
fossil, discovered in the US state of Pennsylvania, shows
that the first limbs evolved on fish to hold themselves up
and to raise their heads. Fish with such limbs lived in
slow, shallow rivers well before vertebrates walked onto
land, the study said. When the animal lived, there were no vertebrates on dry land.
. . The four-legged creature had a humerus, or upper
arm bone. Such a bone, far different from the flipper bones
of fish, gave the creature an important new ability —-it
could raise its upper body like an athlete doing push-ups.
The animal's arm bone fossil has a bony crest that formed
the anchor for powerful chest, or pectoral, muscles. "It
could have evolved this for a variety of reasons, including
pushing its head up out of the water to breathe or to walk
around in shallow water", Shubin said. "And we can't
exclude the possibility that it walked on land." He said
other similar tetrapods from around the same period are known to have had both gills and lungs and, thus, could breathe either under or above the water.
Mar 31, 04: Ostrich egg beads and other artifacts from an
ancient site in Tanzania suggest that humans started
decorating themselves far earlier than once thought, and in
Africa before Europe. The artifacts have not been properly
dated, but the scientists believe they are older than
40,000 years and if so, will challenge two popular theories
--that humans did not develop symbolic thinkking until about
35,000 years ago and that it happened first in Europe.
Researchers are also carbon-dating some of the artifacts to narrow down their age.
. . The site, at the Serengeti National Park, is at
least 40,000 years old and perhaps far older, dating to
what is called the Middle Stone Age. While Middle Stone Age
humans were physically modern, there has been debate about their culture and behavior.
. . In Europe, the equivalent of the Middle Stone Age
is the Middle Paleolithic, when Neandertals lived alongside
physically modern Cro Magnons. While there is limited
evidence that Neandertals may have made jewelry, it is
hotly disputed. Curtis Marean of Arizona State University, who lead the
study, doubts Neandertals were capable of the fine work
like making the tiny white ostrich egg beads found in
Tanzania. There has been no evidence of Neandertals
anywhere but in Europe, where they died out about 30,000 years ago.
Mar 31, 04: The genetic code of the rat joined the growing
list of creatures whose DNA has been mapped and experts
said it will make the laboratory rat, already beloved by
scientists, an even better tool for fighting human disease.
The rat is only the third species to be sequenced to such a
degree. Almost all human genes associated with diseases
have counterparts in the rat genome.
. . The genome of the brown Norway rat —-which
thrives everywhere from subways to cornfields-— is 5
percent smaller in volume than its human equivalent and
slightly larger than the mouse. About 90% of its
estimated 25,000 to 30,000 genes have counterparts in humans and mice.
. . Scientists said that, genetically speaking, rats
were not simply bigger mice. They seem to be smarter. "They
are much further apart in evolution than we are from some
monkeys." Scientists said all three species probably
inherited genes from a common mammalian ancestor about 75 million years ago, not long before dinosaurs went extinct and surviving mammals quickly took their places.
. . But there are some key differences. For example,
the rat relies more heavily on its sense of smell than
humans, and it has more genes devoted to scent detection.
The rat genome also contains expanded genes for dealing
with toxins and other dangers compared to the mouse genome.
. . Perhaps the most surprising finding is how the rodent lineage evolved faster than primates did, implying that rodent genes are more dynamic and adaptable.
March, 04: Chemists in San Diego have created a chemical
compound they call "reversine", which resets muscle cells
in mice much the same way newts restart limb cell growth
after injury. The idea is to turn a patient's skin cells into embryo-like cells that could be coaxed into growing into replacement tissue for failing organs.
The biggest game being stalked in this hunt is finding the
still theoretical genes that launch creation of the human body from a single cell.
Mar 24, 04: A tiny genetic mutation in a single gene that
governs the size of jaw muscles could help explain how
humans diverged from their grunting fellow primates and
rose to become masters of the planet, scientists said. Homo
sapiens has this mutation, which prevents an accumulation
of the protein in those muscles. They discovered that a
fault in a gene called MYH16 in modern humans happened at
about the same time that their skulls started to change in
shape from other primates, allowing their brains to increase in size. "The coincidence in time...may mean that the decrease in jaw muscle size and force eliminated stress on the skull which released an evolutionary constraint on brain growth."
. . All humans have the MYH16 mutation, but other
primates, including chimpanzees and macaques, still have
the intact gene. Over the past few million years, since the
genetic fault occurred, human skulls have grown three times
in size and the outwardly elongated jaws have receded.
. . Research revealed that MYH16 was associated with
muscles involved in chewing and biting and it encoded a
protein in primate jaw muscles. This led the researchers to
suspect the so-called disease in humans was a weaker bite.
They said the weaker bite would have lessened the force on
the skull so it could grow larger and provide more space for a bigger brain.
Mar 10, 04: The boll weevil, the ravenous pest that
dethroned cotton as the king of Southern crops, has been
virtually wiped out across most of the region, thanks to a
20-year program largely funded by farmers. Workers
monitoring traps around cotton fields in Georgia, Virginia,
northern Florida and the Carolinas did not find a single weevil last year.
. . It was a major pest that reduced cotton yields,
forced farmers to spend more on pesticides and worsened
other insect problems. Frequent pesticide spraying in
cotton fields killed beneficial insects that provided free and natural pest control.
They can fly up to 60 miles a day, And you still have
weevils in Mexico, Central America and South America.
Eradication efforts are also under way in some Mexican cotton fields.
Mar 8, 04: A study of the brains of primates ranging from
tiny bush babies to humans and apes shows that size really
may matter, researchers said. All primates have an
unusually large frontal cortex, a part of the brain used by
humans for higher thought and reasoning, they found. From
lemurs to chimpanzees, that part of the brain is especially
large compared with overall brain size. A comparison to
carnivores --the order that includes lions, tigers and dogs-- shows they do not have the same disproportionately large frontal cortex.
. . It turns out that smaller primates such as lemurs
and bush babies actually devote a larger proportion of
their brains to the frontal cortex. But because they are
small overall, this area is small. Humans and apes are big
and have big brains, so while the proportion is not as big,
the frontal cortex ends up being huge, comparatively. This
could explain some behavioral differences that make humans,
apes and monkeys --the large primates-- unique.
. . They found that in primates, the ratio of frontal
cortex to the rest of the cortex was about three times higher in a large primate than in a small one. The ratio does not change in carnivores.
. . They did not look at other notably big-brained
animals such as cetaceans -- the group that includes whales and dolphins.
Mar 4, 04: Genome experts who took on a patch of ocean for
a mass gene-sequencing project said they had discovered at least 1,800 new species of microbes and changed some of their fundamental ideas about ocean biology. Scientists analyzed the tiny organisms in a sample of water from the Sargasso Sea.
. . Called whole-genome shotgun sequencing, it uses powerful
computers to re-assemble the genetic code. They found 1.2
million new genes and, based on what they know about the
genetics of existing organisms and the sample they took,
guess that represents at least 1,800 new species. "It is
estimated that over 99% of species remain to be
discovered. Our work in the Sargasso Sea, an area thought
to have low diversity of species, has shown that there is
much that we do not yet understand about the ocean and its inhabitants."
. . Most surprising, they said, was the discovery of
800 new genes for photoreceptors -- structures used by
creatures to collect light. To date, only about 150
photoreceptor genes have been found in all the known species.
Mar 4, 04: A 6 million-year-old creature that lacked sharp
canines for fighting may be the first pre-human to have
branched off from the ape line. The short, small-brained
creature may provide a good hint of what the common
ancestor of chimpanzees and humans looked like, the researchers said.
. . Fossil remains of the early hominid were found in
Ethiopia three years ago, and it seemed to be a subspecies
of a known pre-human, Ardipithecus ramidus. But the
scientists have found more teeth from a group of the
hominid, re-classified it as a distinct species and named
it Ardipithecus kadabba. "Ardipithecus kadabba may also
represent the first species on the human branch of the
family tree just after the evolutionary split between lines
leading to modern chimpanzees and humans."
. . His team's report suggests that the last common
ancestor of chimps and humans had long canines used to
fight --something chimps have today, but not humans. They
had enough to determine that it was an upright-standing
hominid about the size of a chimpanzee that lived between
5.2 and 5.8 million years ago. One of the most famous pre-
humans, "Lucy" or Australopithecus afarensis, dates back 3
million years. "This doubles the time period all the way
back to 6 million years that a small-brained, small-canine
bipedal early hominid existed", White said.
. . Genetics tells scientists that chimpanzees and
hominids diverged from a common ancestor around 7 million
years ago. "But genetics can't tell us what this animal was like."
Mar 3, 04: Voters along California's wild north coast
defeated the biotech and timber industries, imposing the
nation's first ban on raising genetically engineered crops
and animals and beating back a logging company's effort to
recall a crusading local prosecutor.
. . Activists said today's stunning defeat of
biotechnology in Mendocino County breathes momentum into
similar local efforts just now getting underway nationwide,
setting up a series of regulations the industry desperately
wants to avoid —-and a big reason it spent so much money
here. "This is a start of a revolution."
. . Meanwhile, just across the county line in
Humboldt County, District Attorney Paul Gallegos survived a
recall election with 61% of the vote, despite the
fact that Pacific Lumber Co. spent close to $250,000 to oust him.
. . The campaign to unseat Gallegos came after he
sued the timber giant, accusing it of falsifying data on
landslide risks to get permission to harvest 100,000
redwood trees in a forest it sold to the government for $380 million.
Mar 3, 04: Ants, just like motorists, hate congestion and
use alternative routes to avoid it, scientists said. The
industrious insects push and shove each other out of the way when it gets too crowded, forcing some to find another route from a food source back to the nest.
Mar 1, 04: They've found that the queen ant coats her eggs
with a chemical called a pheromone that prevents worker
ants from laying their own eggs.
. . A team of European researchers wondered about
that, so they studied Capononotus floridanus, a type of ant
living in large colonies. They set up several colonies with
only workers —-no queen-— and added various combinations of
pupae, larvae, and eggs. In colonies that did not receive
queen-laid eggs the workers began to lay their own eggs.
When both queen-laid and worker-laid were added to a
colony, the ants destroyed the worker-laid eggs. Only the
presence of queen-laid eggs inhibited worker reproduction.
. . The researchers analyzed the surface of the queen-
laid eggs and found they contain a special hydrocarbon
blend, very similar to that found on the body of the queen
herself. Adding the chemical blend to the surface of worker-
laid eggs prevented the ants from destroying these eggs.
With a genome five times the size of the human genome,
wheat is so complex that it's one of the last major crops
to undergo genetic manipulation.
Feb 26, 04: Two new species of dinosaur have been
discovered in Antarctica. The 70 million-year-old fossils
of the carnivore rested at the bottom of an Antarctic sea.
The little carnivore was about 2 meters tall.
. . Remains of a 200 million-year-old 100-foot-long
herbivore were found on the top of a 13,000 foot mountain
now known as Mt. Kirkpatrick, an area that was once a soft
riverbed. The animal would have been a primitive sauropod --
a long-necked, four-legged grazer similar to the better known brachiosaurs.
Feb 17, 04: Scientists have unearthed the skeleton of a
prehistoric bird and the remains of its eggs dating back
more than 70 million years, in western Romania. The size of
a blackbird, it is believed to be between 70 and 72 million
years old.
Feb 17, 04: For more than 100 years, researchers have
pondered the odd shape of homo erectus' skull, which looks
something like a bicycle helmet. Designed to protect the
brain, eyes and ears from impact, homo erectus' head was
bulkier than those of hominids before it, and after it.
. . After studying fossils in a region called Dragon
Bone Hill in China, anthropologist Russell Ciochon
concluded males of the species were clubbing one another
over the head, probably to win females. Researchers
compared the mating rituals of the hominids to those of
bighorn sheep. Those with thicker skulls survived, and homo
erectus managed to survive for more than 1.5 million years.
. . Ciochon said evolution eventually favored a
lighter skull to accommodate a heavier and larger brain. A
thinner skull also would help cool the brain.
Feb 13, 04: All dogs originated from a single species,
probably an East Asian wolf seeking the warmth of the human
hearth and an easy meal. "We think there was a series of
domestication events in East Asia", said Norine E. Noonan,
a dog researcher at the College of Charleston in South
Carolina. "It happened a lot longer ago than anybody once
thought —-at least 100,000 years ago."
. . Probably, there was a set of "dog Eves", a
central proto-dog that adopted humans as a protector,
provider and best friend. In return, the early wolf-like
animals helped humans hunt, Noonan said. Based on genetic
research, said Deborah Lynch of the Canine Studies
Institute in Aurora, Ohio, "there were only about a half
dozen domestication events in East Asia."
. . Researchers are now sequencing the dog genome. A
rough genetic map has already been assembled for the
poodle. One for the boxer is expected to be finished in
April. From this, researchers hope to learn the genetic
basis for many diseases that affect both dogs and humans.
Feb 11, 04: Scientists have discovered the remains of a
400 million-year-old insect, the oldest ever located, in a
fossil unearthed in Scotland in the early 1900s. The
discovery pushes back the earliest known insect by 20
million years, but even more importantly it suggests that
winged insects evolved some 80 million years earlier than
previously thought. "Insects would have been among the earliest land animals."
. . One of the biggest questions in evolution is why,
how and when wings in insects evolved. The earliest
evidence of insect wings is from about 330 million years
ago. Specimens from that era show they were fully formed
and capable of maneuvered and powered flight so they evolved earlier.
. . The remains of the early insect consist of a pair
of mandibles, or jaw parts, and additional features that
indicate it is a true insect and a structure that suggests
it belonged to a group of insects that had wings. Its body
would have been about the size of a grain of rice. Because
it was so small, fossils of wings are difficult to find.
Sagan and Salpeter speculated that biological organisms
may have developed in Jupiter's atmosphere, based on
unusual organic molecules produced by the Sun's ultraviolet
light interactions with Jovian molecules. If present, a
complex ecology may develop with primary photosynthetic
autotrophs ('sinkers'), larger organisms that actively
maintain their pressure level ('floaters'), organisms that seek out others ('hunters'), and organisms that live at almost pyrolytic depths ('scavengers').
Feb 5, 04: The secret of carrier pigeons' uncanny ability
to find their way home has been discovered by British
scientists: the feathered navigators follow the roads just
like we do. They fly along motorways, turn at junctions and
even go around roundabouts, adding miles to their journeys.
They use their own navigational system when doing long-distance trips or when a bird does a journey for the first time. But when they have flown a journey more than once
they home in on an habitual route home.
Jan 28, 04: A common painkiller used to relieve the aches
of arthritis is threatening the extinction of three types
of vulture in Asia, conservationists said. Although humans
have been taking diclofenac for two decades, the report
said its use in veterinary medicine is killing rare birds
of prey, which ingest the non-steroidal anti-inflammatory
drug after eating the carcasses of livestock treated with it.
. . "This is the first time a pharmaceutical drug has
been implicated in the decline of large vertebrate wildlife", Dr Rick Watson, the program director of the U.S.-based Peregrine Fund, said.
. . When it was fed to vultures in experiments, the birds suffered from kidney failure.
Jan 27, 04: Rare fossilized tracks of a small mammal
dating to the age of dinosaurs have been found at the
Fossil Trace Golf Course west of Denver. They were
initially interpreted as lizard tracks.
. . The tracks were left by a rat-sized mammal that
hopped across the mud 68 million years ago. The prints and
a similar set found near Rifle, in western Colorado, mark
the first time mammal tracks from the dinosaur age have
been found in the Western United States.
. . Small mammals, none larger than a house cat,
lived alongside dinosaurs for millions of years before the
dinosaurs became extinct 65 million years ago. Their
delicate bones are rarely found, and their tracks are even harder to come by.
. . Tracks left by horned dinosaurs and crocodile-
like champsosaurs have previously been found at the Fossil Trace course.
Jan 25, 04: Danish researchers said they have produced a
plant that can help detect hidden landmines by changing its
color from green to red when its roots come in contact with
explosives. Initial testing will take place in Bosnia, Sri
Lanka and parts of Africa. The genetic makeup of the plant
does not allow it to spread without the help of humans. "This is crucial since we have to be able to control its growth where we plant it", he said.
. . Some 100 million unexploded landmines are
believed to be lurking in the soil of about 75 countries the world over.
. . The problem of sowing the seeds in a potential
land mine could be overcome by clearing strips through a
field by conventional methods or by using crop planes.
Today, flatworms occupy virtually every habitat on Earth
and number about 25,000 species in all.
Jan 26, 04: Like many plants, when attacked by insects,
corn releases chemicals called green leafy volatiles into
the air, a research team reports. When released into the
air, green leafy volatiles smell like cut grass or crushed
leaves, an odor that can attract predators that are the
natural enemies of the insect eating the plant.
. . In addition, these compounds serve as an early
warning system to other nearby plants. "The (green leafy
volatiles) appear to be like a vaccine, turning on the
defensive mechanism but not pushing it to full strength. If
the plant is not attacked, then it does not waste energy producing defenses. However, if it is attacked, the response is more rapid and stronger."
Jan 25, 04: A millipede whose fossilized remains were
discovered last year in eastern Scotland is the earth's
oldest known land-dwelling creature, according to
scientists. Paleontologists from the Scottish National
Museums and Yale University in the United States have
concluded that the creature is more than 420 million years old.
Jan 22, 04: There could be public health and agricultural
benefits from the creation of genetically modified insects,
but the practice needs to be regulated, according to a
report from the Pew Initiative on Food and Biotechnology.
. . The report cites among the most encouraging
research the creation of mosquitoes incapable of
transmitting malaria, honeybees genetically engineered to
be resistant to diseases and parasites and kissing bugs
unable to transmit Chagas' disease, which infects 16-18
million people and kills another 50,000 a year.
. . "However, there is uncertainty about the lasting
effects these insects could have on ecosystems, public
health and food safety, once released."
Jan 22, 04: A Vanderbilt University biologist is hoping to
build a better mosquito trap by finding out how to disable
the pesky bug's sniffer. Researchers say their work,
published in the journal Nature, identifies a single gene
that responds specifically to one of the 350 or so smell-
producing compounds in human sweat. The work could lead to
better repellants and ways to produce attractants that
would lead mosquitoes into deadly traps. Last year, the
mosquito-borne West Nile virus killed 220 people in the
United States, and malaria kills at least 1 million people worldwide every year.
. . The centuries-old war on mosquitoes got a major
boost in 2002 when an international coalition of scientists
completed a full map of the approximately 16,000 genes in
the mosquito primarily responsible for spreading malaria.
. . The work focused on the genes in female mosquitoes, which do all the blood sucking.
Jan 14, 04: Researchers said they had found a gene that
seems to put people more at risk of alcoholism, but said
they cannot yet explain how it works. "It is likely that
many genes that influence alcoholism act through indirect
pathways. In other words, there is no gene that directly causes you to become alcoholic, but rather there are genes that alter your risk of becoming alcoholic."
Jan 8, 04: A squid with a novel type of reflective plates
that form a built-in light it may use to confuse predators
has been discovered by scientists in Hawaii. The light
itself is provided by colonies of luminescent bacteria that
live on the squids. "...the light organ does have a lens
similar to an eye in some respects, but we don't really
know its capabilities in terms of specifically directing light."
. . The two- to three-inch squids forage and mate at
night and predators that eat them tend to hide in the sand,
looking upward. "We think it projects light down, and that
looks like moonlight so the squid doesn't cast a shadow and
is not silhouetted against the night sky."
. . While reflective plates in many aquatic species
are formed from chemicals called purines, in this squid
they were made from an unusual type of protein the researchers named reflectin.
A bacteria named psychrobacter cryopegella can continue to
metabolize even at temperatures down to -20 Celsius (-4
degrees Fahrenheit), though they understandably stop reproducing at that extreme.
Dec 27, 03: Brazil nuts, strictly, are not nuts at all,
but seeds, up to 25 of which are packed tightly inside a
hard woody fruit the size of a large grapefruit.
. . They are the only seed crop traded
internationally which have to be collected from the wild.
Attempts to grow Brazils in artificial plantations have
failed, because the trees produce fruit only in the forest.
Populations of trees picked heavily over many years produce
very few young trees, threatening the species' future.
Dec 28, 03: Neandertals were shedding their sturdy
physique and evolving in the direction of modern humans
just before they disappeared from the fossil record. Newly
identified remains from Vindija in Croatia, which date to
between 42,000 and 28,000 years ago, are more delicate than "classic" Neanderthals.
. . Dr Ahern thinks that Neanderthals and modern
humans in Africa were evolving in the same direction in
response to common environmental pressures. "They were
evolving in the same way because they were part of a larger
human species. Neanderthals just didn't change as rapidly
as some of the other people", he explained. These pressures
may have been rooted in sharp changes in the global climate.
. . Comparisons of mitochondrial DNA from Neanderthals and modern humans have failed to reveal any signs of mixing between the two populations.
Out of 24,000 clearly identified human genes, we share at least 18,000 with dogs.
. . A study confirms that, while dogs and wolves
diverged from the common ancestor of all mammals long before early humans and mice did, dogs are much more closely related to humans than mice are.
. . Last Human/Orangutan common ancestor: 12 M.Y. ago.
. . They figure that, 100K ago, there were 33 women
to whom we can trace all of our descent.
Dec 10, 03: The first gene map of our closest relative,
the chimpanzee, is drafted and on the Internet for anyone
to look at, U.S. researchers said. They have also lined up
the genome map of the chimp with the completed map of
humans, to make comparisons easier.
. . "Chimpanzees are the most closely related species
to humans", the National Human Genome Research Institute,
one of the National Institutes of Health, said.
. . An international team of scientists, led by
researchers at the University of Washington in Seattle,
Washington University and the Broad Institute at MIT and
Harvard University, is currently comparing the chimp and
human genome sequences and plans to publish results of its
analysis in the next several months.
According to most paleoanthropologists, Homo heidelbergensis gave rise to modern humans in Africa and Neandertals in Europe.
Svante Pääbo of the University of Munich and colleagues in
Germany and the United States successfully extracted the
DNA from a right humerus (upper arm bone) of a Neandertal.
. . The comparison to chimpanzees with modern humans
is 55.0 ±3.0, compared to the average between humans and
Neanderthals of 25.6 ±2.2. These results indicate a
divergence of the human and Neandertal lineages long
before the most recent common mtDNA ancestor of humans.
Based on the estimated divergence date of 4-5 million years
ago for humans and chimpanzees, the authors estimate the
human and Neandertal divergence at 550,000-690,000 years
ago. The age of the common human ancestor, using the same
procedure, is about 120,000-150,000 years ago.
. . In March of 2000, the results of a second fossil
Neandertal DNA sequencing was announced in the Journal
Nature (Ovchinnikov, et. al., 2000). The fossil specimen is
an infant from the Caucasus region dating to less than
30,000 years ago. A rib was used in the DNA isolation and
345 base pair sequence was produced. The specimen had 22
base pair differences, compared to 27 for the type
specimen, over the 345 base pair sequence. The two
Neanderthals share 19 substitutions. Although the two
Neanderthals were separated by 2,500 km, they are closely related in mtDNA lineages.
. . This second study estimates the most recent
common ancestor among the Neanderthals at 151,000 - 352,000
years, while the human and Neanderthal divergence is placed
at 365,000 - 853,000 years. The same model produces an age
for the modern human divergence of 106,000 - 246,000 years.
. . They found that the differences in Neandertal DNA
occurred at sites where differences usually occur in both humans and chimps.
Dec 10, 03: Scientists in the US have coaxed stem cells
from mice to change into immature sperm that can fertilize
eggs to develop into embryos, an achievement that could
pave the way for new ways of treating male infertility.
They plan to transfer the embryos into female mice to see if they develop normally.
. . Although they are found in adult tissue, the most
flexible stem cells come from early embryos.
Dec 11, 03: A comparison of genomes in man and the
chimpanzee suggests that a genetic divergence in hearing
may have allowed man to develop speech while leaving the
chimpanzee verbally challenged, said a US study.
. . The comparative study of the genetic makeups of
people and chimps, which are genetically almost 99%
identical, showed that some processes such as hearing and
smell evolved more rapidly in humans.
. . A team sequenced more than 7,000 chimpanzee genes
before comparing them to the same genes in humans and in
monkeys. They found that several genes involved in the
development of the inner ear and hearing appeared to have
undergone genetic selection in man. Researchers put forward
the hypotheses that human language development would have required sharper hearing.
Dec 3, 03: Fossils discovered in Ethiopia's highlands are
a missing piece in the puzzle of how African mammals
evolved, a team of international scientists said.
. . Little is known about what happened to mammals
between 24 to 32 million years ago, when Africa and Arabia
were still joined together in a single continent. But the
remains of ancestors of modern-day elephants and other
animals, unearthed by the team of U.S. and Ethiopian
scientists 27 million years on, provide some answers.
. . Using high-resolution satellite images to scour a
remote area where others had not looked before, his team
found the remains in sedimentary rocks about 2Km above sea level.
Nov 1, 03: Low oxygen levels could have triggered two
giant extinctions hundreds of millions of years ago, allowing the dinosaurs to reign supreme over the ancestors of mammals, U.S. researchers said.
. . Dinosaurs first appeared during a long period of
low oxygen and therefore developed highly efficient
breathing mechanisms that allowed them to thrive while many
other species became extinct. The researchers arrived at
the theory by tying in what is known about the physiology
of dinosaurs with recent geological evidence suggesting
that from 275 million to 175 million years ago, oxygen
levels stayed very low --comparable to levels found now at altitudes of 14,000 feet.
. . Peter Ward, a paleontologist, said he believes
low oxygen and hot greenhouse conditions caused by intense
volcanic activity may have caused widespread extinctions
250 million years ago, at the boundary between the Permian
and Triassic periods, and about 200 million years ago, at
the boundary between the Triassic and Jurassic periods. The
Permian-Triassic extinction is believed to have eradicated
90% of all species on Earth, including most
protomammals, the immediate ancestors of true mammals.
. . The Triassic-Jurassic extinction killed more than half the species, including many mammals and mammal-like reptiles. But dinosaurs flourished.
. . Ward said he put together three pieces of the
puzzle --the extremely efficient breathing systems of
birds, the finding that many dinosaurs had similar physiology, and a report that came out earlier this year showing that oxygen levels were low during the two extinctions.
. . Birds and dinosaurs both have holes in their
bones. And many of the largest dinosaurs, such as
brontosaurus or apatosaurus, seem to have had lungs
attached to a series of thin-walled air sacs that may have
acted something like bellows to move air through the body.
"The reason the birds developed these systems is that they arose from dinosaurs halfway through the Jurassic Period. They are how the dinosaurs survived."
. . "However, when we considered that birds fly at
altitudes where oxygen is significantly lower, we finally
put it all together with the fact that the oxygen level at
the surface was only 10% to 11% at the time the dinosaurs evolved."
Currently at sea level, atmospheric oxygen levels are 21%.
Nov 24, 03: Among baboons, moms with lots of female
friends are the most successful parents, according to a new
study that supports the idea that social support is an
essential part of being a baboon —-or a human.
Nov 13, 03: Ancient Americans were changing corn genes
through selective breeding more than 4,000 years ago,
according to researchers who say the modifications produced
the large cobs and fat kernels. By cultivating plants with
desirable characteristics, farmers caused teosinte to morph
into an increasingly useful crop.
. . The ancestral plant of corn, teosinte, was first
domesticated some 6,000 to 9,000 years ago in the Balsas
River Valley of southern Mexico, the researchers said in
this week's issue of Science magazine. At first, teosinte was a grassy-like plant with many stems bearing small cobs with kernels sheathed in hard shells.
. . One gene changed the architecture of corn from a
plant with many branches to one with a single stalk with a
male tassel at the top and female cobs growing along the side.
. . Another genetic change softened the outer hull on the kernel.
. . Another caused the kernels to stick more tightly
to the cob. And still another change modified the starch of the grain. This final change, the authors wrote, made the corn more suitable for making tortillas.
. . The effect, she said, was like "a prehistoric Green Revolution."
Nov 10, 03: Hiding in cool coastal mountain streams from
California's Mendocino County north to Canada are odd
amphibians that have survived since the days of the
dinosaurs —-but are so sensitive they'll die in the heat of
a human hand. Scientists view amphibians as indicator
species to gauge the health of forests and watersheds.
Clear-cutting can require 50 to 60 years for the forest to recover the microsystems amphibians need to survive. As the amphibians go, so go the salmon.
Nov 6, 03: There are more proteins than genes in humans --
about 250,000 proteins versus 30,000 genes. These tens of
thousands of proteins then can interact in innumerable
ways. To understand biology and disease and to find new
drugs, scientists will have to understand these interactions.
. . Scientists published today what they said was the
first protein map of a complex organism, a fruit fly,
moving beyond charts that simply show what the genetic code
looks like and beginning to show what it actually does.
Their map of more than 7,000 proteins covers more than
20,000 different interaction of those proteins.
Nov 5, 03: Curved grooves on the roots of teeth from
ancient hominids suggest they were indeed concerned about
dental hygiene and used implements to pick their teeth. But
critics of the hypothesis have pointed out that modern
humans who regularly use toothpicks do not have similar grooves.
. . Well, maybe floss. "Unlike wood, grass contains
large numbers of hard, abrasive silica particles. This may
explain the grooves seen on ancient teeth." To prove the
point, Hlusko ground a piece of grass along a tooth from a
baboon and also on a human tooth. "In both, the grass left
marks almost identical to those seen in scanning electron
microscopic images of early hominid teeth."
. . Dental grooves have been found on fossil teeth
dating back 1.8 million years. If it was made by toothpicks
it could qualify as the oldest human custom yet recorded.
Oct 29, 03: Scientists have delved into the virtual brains
of 100 million year old extinct flying reptiles to discover
how the creatures conquered the skies.
. . Pterosaurs, the largest animals that ever flew,
were able to soar through the air while dinosaurs roamed
below and could swoop down on unsuspecting prey because of
their specialized brains, they said.
. . Using high-tech scans, computer generated images
and rare fossil skulls from two types of the creatures, a
team of researchers recreated their virtual brains to
uncover new clues about how flight evolved. "We were able to reconstruct what the brains and inner ear canals looked like, in the virtual realm."
. . Pterosaurs evolved into species ranging from a
tiny bird-sized creature to massive fliers with a 12 meter
wingspan, developed flight independently from birds.
. . In pterosaurs, part of the brain called the flocculus,
which control movement, was much larger than in birds. It
processes information on body, neck and head position and
relays it to the muscles that move the eyes. With the large
flocculus to process information, the pterosaurs would have
been equipped with "smart" wings that would have given them
excellent flight control. "Despite their antiquity, they
could have outperformed modern birds and bats."
Oct 29, 03: Young dolphins have long baffled scientists by
seeming to swim fast enough to keep up with their mothers,
but according to new research they are sucked along in a
slipstream. An aerospace engineer who studied the mammals
in San Diego found that calves position themselves between
10 to 30 cm away from their mother's body and align the
midpoint of their bodies with her tail. The calves swim so
close to their mothers that they get sucked along at speeds
of up to five knots. The calf encounters 65% less resistance.
Oct 23, 03: Scientists at the University of California San
Francisco said they had created worms that lived six times
longer than normal. The gene they tinkered with also
affects lifespans in higher animals such as mammals. You
don't even have to get decrepit --but you do have to tolerate a little genetic tinkering and, oh yes, the removal of your reproductive organs.
. . Their tiny roundworms lived for three months or
longer, as compared to 18 or 20 days for a normal worm. "In
human terms, these animals would correspond to healthy, active 500-year-olds."
. . One gene that interested them is IGF-1 or insulin
growth factor -- a gene that helps regulate how the body
uses insulin, itself a regulator of metabolism.
Certain mutations of the gene double a worm's lifespan by weakening the effects of IGF-1, and removing their reproductive systems doubles it again.
. . Kenyon's team added another layer of tinkering,
breeding worms with the mutation to IGF-1 and then using a
genetic technique called RNA interference to further weaken
the gene's function. These worms lived even longer.
Oct 24, 03: Scandinavian researchers concluded that the
walruses used their right flippers 66% of the time,
and their left flippers only 4%. The animals used
their muzzles 29% of the time and the water jet only
1%. Underwater footage of walruses cavorting in the
wild shows that the animals prefer to use the right flipper
over the left, a scientist said.
Oct 23, 03: Scientists reported they had found the first
evidence of a brain tumor in a dinosaur, in the fossilized
remains of a creature that lived 72 million years ago in
present-day Montana. Evidence of the tumor was found in a
fossil of a 25-foot-long predator called Gorgosaurus, a
meat-eater closely related to Tyrannosaurus rex.
. . "We do know that it was life-threatening, and if
it did not directly cause death, it led up to it." He said
the finding is significant because it is the first brain
tumor found in any kind of fossil --dinosaur or otherwise.
. . The ball-shaped mass was about two inches in
diameter in a brain that was about half the mass of a human
brain. The tumor took up almost all of the cerebrum, the
part of the brain that processes higher thought, and was
pressing against the brain stem, Larson said.
Oct 22, 03: Whether it's a tiny crustacean or a 5-foot-long fish, creatures that spontaneously change their sex do it when they reach 72% of their maximum size,
scientists said. Spontaneous sex change is relatively
common in lower aquatic species with simple reproductive systems. Half of the creatures will change from male to female and the rest will switch the other way.
Oct 22, 03: Scientists discovered a new bird species, but
its habitat is threatened by a dam project in a
southeastern Venezuela river basin, a British environmental organization announced.
Oct 22, 03: A tadpole-shaped fossil, believed to be the
oldest vertebrate ever found, has been uncovered by a
farmer in a rugged range of hills in southern Australia, a
museum paleontologist said. The fossil, of a 26-inch
fishlike animal, is believed to be at least 560 million
years old — 30 million years older than the previous record.
Oct 22, 03: Scientists in Britain have finished the
analysis of human chromosome "6" which contains genes
linked to the body's immune response against bacteria and
viruses. It is the largest of the 23 pairs of human
chromosomes completed so far, with 2,190 genes, and forms
nearly 6% of the entire human genome.
. . Researchers are now analyzing each chromosome,
strands of tightly packaged DNA, to learn how to prevent,
diagnose and treat diseases. "These genes on chromosome 6
are involved in breaking down small bits of the invading
pathogen and presenting it on the cell surface." The
foreign bits are recognized by other cells that realize it is infected and kill it.
. . About 1,557 genes on chromosome 6 are thought to
be functional. Beck and his team have identified roughly
130 genes that somehow cause or predispose humans to
certain diseases. "Most of diseases that are implicated
here are complex diseases, meaning that many genes are
implicated but there are single gene disorders included as well."
. . The PARK2 gene, which is involved in a form of
Parkinson's disease that strikes early, and the HFE gene
which is linked to hereditary hemochromatosis are also on chromosome 6.
. . Chromosomes 20, 21, 22, 7, 14 and Y have also been completed.
Oct 15, 03: A new species of frog, whose ancestors hopped
around at the feet of the dinosaurs, has been discovered in
the mountains of southern India, scientists said.
. . The purple, small-headed creature with tiny eyes,
protruding snout and a bloated appearance belongs to a new
family of frogs that scientists thought had either never
existed or had disappeared without trace millions of years ago.
. . "It is not just a new species. It represents a
deep branch in the evolutionary tree of frogs, and as such
merits the establishment of a new family." "You could say it is a living fossil."
. . Scientists had estimated that the family tree of
frogs diverged about 230 million years ago. "This (the
discovery) tells us that there was a frog lineage in Indo-
Madagascar when it was one continent about 130 million years ago."
. . Only 29 families of frogs are known and most were
identified and described in the mid-1800s and the last in 1926.
Oct 9, 03: A honeybee turns on and off 40% of her
genes as she matures from being a "nurse" to a forager in
her short, busy life. The bees mature into new roles over a
period of two to three weeks. Nurse bees care for the young
for their first two to three weeks of life, then shift to
foraging for nectar and pollen. But if the colony is short
of foragers, for example, some of the nurse bees will mature more quickly. All of this happens fast. A honeybee typically lives just six weeks.
Oct 9, 03: That "kicked in the gut" feeling is real, U.S.
scientists said. Brain imaging studies show that a social
snub affects the brain precisely the way visceral pain
does. The area affected is the anterior cingulate cortex, a
part of the brain known to be involved in the emotional
response to pain. But there also seems to be a defense
mechanism to prevent the pain of rejection from becoming
overwhelming. "We also saw this area in the prefrontal
cortex. The more it is active in response to pain, the less subjective pain you feel."
Oct 6, 03: What's the best way to keep from being eaten:
Keep mustering new defenses, or create a single
overwhelming one and warn potential attackers that they'll
be sorry? Both approaches seem to work, according to new
research. Some plants and beetles adapt to one another by
evolving new attack and defense strategies, while poisonous
frogs develop bright colors to warn predators that biting them can be a fatal error.
. . Scientists thought the development occurred only
once in a species' development because the poisons are so
complex. But the team studied the animal's DNA to map when
various traits were acquired and found that the poisons and
bright coloring had evolved several times in various varieties of frogs.
. . In a separate paper in PNAS, Judith X. Becerra of
the University of Arizona, Tucson, reports on the evolving
relationship between plant-eating beetles and their target
plants as the two evolved defense and attack strategies
through the centuries. The plants and beetles forced each
other to continue adapting as they alternated strategies in
a process called coevolution. Becerra says her study, by
dating the ploy and counterploy between specific species,
provided the first direct evidence of synchronous changes.
. . She worked out a timeline for the development of
various traits in the plants and beetles over 112 million
years, and found the two locked in a series of defense and
attack steps. Some species of Bursera, for example, evolved
the trait of holding toxic resins under pressure so that
when a leaf is damaged, such as by being chomped by a
beetle, the resin would squirt out. Besides being toxic,
the resins solidify in the air, potentially encasing small
insects. That was followed by the development of species of
beetles that learned to cut leaf veins, releasing the
pressure, before beginning to eat the leaves. Other species
of the plants then evolved a series of complex toxic chemicals to repel insects, followed by the development of beetles that could safely ingest those chemicals.
Sept 22, 03: A jawbone found in a cave in Romania may be
evidence of the earliest modern humans in Europe, living at
the same time as the last of the Neandertals. They've
dated the bone at 34,000 to 36,000 years ago. The early
date for the jawbone makes it the oldest from a modern
human found in Europe, though Trinkaus said it retained
some earlier characteristics, including extremely large wisdom teeth.
Sept 22, 03: Scientists hope DNA analysis will reveal
the origins of large, mysterious apes discovered in the
heart of Africa. Genetics research has begun at Omaha's
Henry Doorly Zoo on fecal samples collected this summer
from the rare apes to determine if they make up a new
species, a new subspecies or some form of hybrid —-possibly
a mix between a chimpanzee and a gorilla. But it may be impossible to determine the apes' entire ancestry without getting a sample of blood or tissue.
. . The apes, which stand five to six feet tall and have feet nearly 14 inches long, were first documented last year the Democratic Republic of Congo.
. . They have bodies similar to those of gorillas,
but generally the facial characteristics of a chimpanzee.
The animals sleep on the ground at night like gorillas, but
eat a fruit-rich diet like chimpanzees. What makes the
gorilla-like apes even more unusual is that the closest
gorillas documented in that part of Africa are thousands of miles away.
. . Biologically, it is possible for a chimpanzee
and a gorilla to have viable, fertile offspring.
Sept 18, 03: The fossil of a 1,500-pound animal, 9 feet
long, belonged to a rodent -- an early ancestor of modern
guinea pigs, researchers reported. It had a long tail for
balancing on its hind legs and continuously growing teeth.
Living 8 million years ago in what is now Venezuela, the
animal would have grazed and from a distance would have
resembled a buffalo (that's the animal that pulls plows).
. . "Phoberomys is reported to be the largest rodent that ever existed", more than 10 times the mass of the largest living rodent, the capybara.
. . Its bones and teeth suggest the animal, nicknamed
Goya, munched grass. Larger animals are more successful
grazers, Alexander said in a commentary, perhaps because
they have bigger stomachs to digest their fibrous meals.
No one can explain precisely why an estimated 13%
of the world's population is left-handed. There is a high
tendency in twins for one to be left-handed.
Sept 17, 03: When it comes to fair play, capuchin monkeys
don't settle for any funny business. They demand their
equal share of food or rewards for tasks they've done. They
won't settle for an injustice and are miffed when they
think they have been cheated, researchers said. "It's the
first time a sense of fairness has been found in any
nonhuman, at least to our knowledge."
. . They're small brown primates from central and South America.
. . They received food in exchange for doing a
certain task. But each partner did not always get the same
quantity or quality of food for equal amounts of effort. If
both members of the pair did not get the same reward, the
monkey that was short-changed refused to accept it or threw
it away, in a reaction similar to that of humans.
. . The scientists are now testing chimpanzees to see
if they have the same reaction to fair play.
Sept 17, 03: Scientists have found the best evidence yet
that plants appeared on land about 475 million years ago,
50 million years earlier than fossils had established
before. In the new study, the spores were found with the
spore sac that produced them, indicating they came from a
land-based plant. The spores are similar to those from a
moss-like plant known as a liverwort, which can still be found today.
. . They were discovered by sieving through core
samples drilled in the search for oil, in this case a 4,950-
foot-deep core drilled in northern Oman. Wellman's group
dissolved the rock in a type of acid that does not destroy
organic matter, and then strained the acid to find the spores and plant fragments.
. . "If you were walking about on Earth back then, to
see anything at all you would have been on your hands and
knees with hand lens", Kenrick said. "Sort of like Sherlock
Holmes, looking through a magnifying glass at all of these
things. Life was on a completely different scale."
Sept 15, 03: Contrary to popular scientific belief,
individual genes may be responsible for more than one
learning disorder, according to a major study into twins.
Plomin said too much time and energy had been focused on
trying to isolate specific genes and associate them with
specific learning disabilities. This was too blinkered an
approach which his study showed to be flawed, he said.
Sept 12, 03: Increased findings that weeds are developing
resistance to Roundup, the world's most popular herbicide,
have some scientists urging new planting practices. The
product's manufacturer says the problem is being overblown.
. . Roundup, whose generic name is glyphosate, has
been on the market for more than 30 years. It long has been
a favorite of farmers, home gardeners and golf course
greenskeepers because of its effectiveness in killing
weeds. It allows growers to cut back on tilling, a more
labor-intensive and expensive method of controlling weeds,
and does not pollute the environment.
. . The herbicide is vital for food production
systems in the United States and in many other parts of the
world, Powles said. Should weed resistance become
widespread, he said, "I think the problem will become a crisis."
. . In 1996, Australia was the first to note that
weed resistance to glyphosate was developing in rigid
ryegrass found in a few grain and sorghum fields. Five
years later, South Africa reported seeing the resilient
rigid ryegrass had infested a few hundred acres of vineyards.
. . Resistant mare's tail has been reported in other
states — Indiana, Kentucky, Maryland, New Jersey, Ohio,
Arkansas, Mississippi and Tennessee. Far more worrisome are
cases in Iowa, Illinois and Missouri, where glyphosate is
becoming ineffective on abundant weeds such as velvet leaf and water hemp.
Sept 9, 03: Alligators have the fiercest bite, according
to researchers who found the reptiles have more clamping
power in their jaws than hyenas, lions or the dusky shark.
Three researchers found that a 12-footer at a St. Augustine
alligator farm bit down with the weight of a "small sedan", or 2,125 pounds. A larger gator chomped down much harder, with a bite force of 2,960 pounds.
. . Gators use their powerful mouths, filled with
about 80 teeth, to catch and crush hard-shelled freshwater
turtles for food. They also have used that force in human
encounters. Thirteen people in Florida have died from alligator attacks since 1948.
Sept 3, 03: Southern Africa has an elephant overpopulation
problem. Take a piece of the African bush, enclose it with
a fence and let the world's largest land mammal reproduce
as it pleases. After a while, you will have a jumbo-sized
problem on your hands. Elephants have big appetites, with
adults consuming on average around 375 pounds of food a
day. They are increasing at about 7% a year. In 10
years, it will double... they have a long life and low
mortality rates. Scientists are experimenting with
contraceptives and relocation, neither with much hope.
. . "In any protected area that has elephants, you
have two choices --you utilize the area to maintain
biodiversity, or else you have an elephant sanctuary; you
can't have both", says Dr. Ian Whyte, a biologist with South African National Parks.
Sept 3, 03: Scientists compared DNA. Elephants on Borneo
are a distinct subspecies with bigger ears and straighter
tusks than cousins on Sumatra and mainland Asia and special
care should be taken to save them, the World Wide Fund for Nature said.
Borneo's elephants were separated from their mainland
Asian and Sumatran cousins about 300,000 years ago. The
findings scotched a theory that elephants in Sabah were
descendants of tame ones given by the British East India
Company to the Sultan of Sulu a couple of centuries ago.
Aug 30, 03: Scientists say they may have worked out how
spiders and silkworms are able to produce such strong
fibers to spin their webs and cocoons. "The organism dumps
protein into the gland but as it does that, it regulates
how much water it leaves in there. That controls the entire
process." They say that if they are right, their research
could be used to produce silk in the laboratory for extra-
strong protective clothing, sports equipment and even replacement bone tissue.
. . Silk is the strongest natural fiber known to man
but scientists have yet to replicate its strength.
AUG 28, 03: Scientists discovered 10 new fish species and
a previously unknown species of shrimp in a southeastern
Venezuela river basin. Conservation International said it
hoped the discoveries would ensure preservation of the Caura River Basin.
Aug 22, 03: Researchers who've created a fast-growing
oyster strain have planted 180,000 juvenile oysters in
rivers and waterways to see if they're capable of giving
Maine oyster farmers an advantage. Nine oyster growers from
the Cousins River in Freeport to Cutler Harbor in
Washington County have planted the oysters that scientists
say are capable of growing to market size in just two
years. Fast-growing, disease-resistant oysters would
provide an advantage over typical Maine-grown oysters that take three to four years to reach market size because the cold water sends them into hibernation.
Aug 16, 03: A study that looked at the most intimate of
pests --body lice-- suggests that humans started wearing
clothes 70,000 years ago, scientists said. The genetic
study of lice strongly suggests they --and clothing-- arose
soon after modern homo sapiens began moving out of Africa
and into the cooler regions of Europe.
. . Only humans carry this particular species of
louse, which lays its eggs in clothing. Three species of
louse infect humans --head lice, body lice and crabs or
pubic lice. Experts agree that body lice are a subspecies
of head lice and that body lice probably evolved when
people started to wear clothing.
. . The team used a molecular clock to find out when
body lice evolved. They looked at the DNA found in the
mitochondria of cells. This DNA is inherited virtually
intact from the mother, with any changes happening through
mutation alone. The rate of mutation can be calculated,
with a certain number of changes expected with each
generation. By comparing the mitochondrial DNA of body lice
to that of a cousin --chimpanzee lice-- the researchers
were able to date it back to around 70,000 years ago. This,
they said, fits in with growing evidence that modern humans
evolved in Africa and migrated out around 100,000 years ago.
. . They are also starting to look at pubic lice, or
crabs. He at first believed they might shed light on when
humans lost their heavy body hair. "But I found out that
entomologists and taxonomists pretty much are united in
agreeing that human pubic lice are more related to gorilla lice than to head lice.
Aug 15, 03: Twins are less likely to commit suicide than
other people, scientists said. Researchers in Denmark
looked at the records of more than 20,000 same sex twins
who died between 1943 and 1993, and compared their rates of
suicide with the wider population. They found that the suicide rate was lower for twins, regardless of their sex. This contradicts earlier studies.
Aug 13, 03: A comparison of human DNA to 12 other animals
shows we share more than our genes and helps show that
people are more closely related to rats than to cats, U.S. scientists reported.
. . The survey also adds to the argument that so-
called "junk" DNA is nothing of the sort, but must do
something important because it stays virtually identical
across many species. It also supports what is becoming
increasingly clear --that the stretches of DNA we call
genes are only a small part of the genetic story.
Aug 13, 03: Single-celled marine organisms called
phytoplankton have trim and efficient little genomes that
help them work as floating solar panels, international
researchers said. A comparison of four different species of
tiny plankton shows they can do their job --collecting
sunlight and turning it into food-- with just a few genes.
. . Understanding how they do this could help
humanity one day better harness sunlight as a power source
and even lead to ways of battling global warming. "It
behooves us to understand exactly how, with roughly 2,000
genes, this tiny cell converts solar energy into living
biomass -- basic elements into life."
. . They dominate the oceans. There are some 100
million Prochlorococcus cells per liter of seawater. They
also "fix" two-thirds of the carbon in the ocean -- meaning
they take carbon from the atmosphere and use it in building
their own small cells. They also produce a huge amount of
oxygen in doing so. This suggests an important role in global warming.
"A hundred of these organisms can fit end to end across
the width of a human hair, but they grow in such abundance
that, as small as they are, they at times amount to more
than 50% of the photosynthetic biomass in the oceans."
Aug 14, 03: U.S. and Indian scientists said they have
discovered a new carnivorous dinosaur species in India
after finding bones in the western part of the country. The
dinosaurs were 7-10 meters long, had a horn above their
skulls, were relatively heavy and walked on two legs.
"People don't realize dinosaurs are the only large-bodied
animal that lived, evolved and died at a time when all
continents were united", Sereno said.
Aug 15, 03: Male moths may be convinced love is in the air
when an Australian town saturates the sky with female
pheromones, but scientists struggling to cut their numbers
hope they will be too overwhelmed to find females to mate
with. They hope the use of the pheromones would help cut
the use of pesticides on crops in the area.
Aug 14, 03: A microbe that thrives in boiling water and
"breathes" iron has stretched the limits of where
scientists believed life could exist, according to a report.
. . The bacteria-like organism lives in a hellish
undersea environment where water boils out from underwater
vents called black smokers. There is no light, the pressure
of the water would instantly crush anything living on land
and the water is loaded with toxic chemicals.
. . The discovery suggests that life could exist on
planets very different from Earth. It also suggests that
life did not always evolve in the ways biology teaches --in
warm, soupy waters bathed in sunlight on the planet's surface.
. . Another microbe, called Pyrolobus fumarii, lives
in temperatures of up to 113 Celsius. But the newly
discovered microbe survived even higher temperatures and
did not use either oxygen or sulfur in respiration. Instead
it uses iron to burn its food for energy --the role played
by oxygen on most other species on Earth.
. . They tested their sample by steaming it in an
autoclave --used to disinfect medical equipment. To their
surprise, they were able to grow this organism even after
bringing the water to temperatures far above the boiling
point --up to 121 degrees Celsius. It doubled in cell
numbers after 24 hours at 121 decrees C."
Aug 4, 03: In a study that shows more than ever you are
what you eat, U.S. scientists said they had changed the
coat colors of baby mice simply by altering their mothers'
diets. The study shows that common nutrients can influence
which genes turn on and off in a developing fetus, and help
explain some of the factors that decide which genes "express" and which remain silent.
. . The scientists at Duke University Medical Center
said they changed the color of baby mouse fur by feeding
pregnant mice four supplements --vitamin B12, folic acid,
choline and betaine. Mice given the four supplements gave
birth to babies predominantly with brown coats. Pregnant
mice not fed the supplements gave birth mostly to babies with yellow coats.
Aug 5, 03: Europe's bee-keepers received a stern warning
to guard against the arrival of an exotic new pest which
could wipe out entire bee colonies if it gains a foothold
on the continent. The small hive beetle has not yet been
seen in Europe, according to the EU's executive Commission.
"It's a developing parasite and nobody knows exactly where
it is in the world. We don't believe that it is yet in
Europe. It has a very destructive impact on bees and destroys the whole stock."
. . Also known by its Latin name, aethina tumida, the beetle
is native to sub-Saharan Africa but has spread to South
Africa, the United States and Australia in the last few years.
. . This rule also applies to another pest known as
tropilaelaps coleopteren, a parastic mite smaller than the
hive beetle that can cause high death rates as well as leg and wing deformities.
July 30, 03: Big, assertive guys don't always get the
girls. In some species, such as coho salmon and quail,
weedier, less aggressive males are the top choice of
females, New Scientist magazine said. They proved the point
by observing Japanese quail. After female quail watched a
fight between two males they were put in the same cage with
the combatants. Virgin females preferred the winner but the
females with some sexual experience tended to choose the
loser. Female coho salmon are also more likely to mate with
males known as jacks who stop growing earlier and are smaller than their competitors.
July 30, 03: A common farm pest appears to have
leapfrogged over the flea to claim the unofficial title as
the world's best jumper. British researchers say
experiments show the spittle bug —-a tiny, green insect
that sucks the juice from alfalfa and clover-— can leap
more than 2 feet in the air. That's more than twice as high as the flea.
. . The 6 millimeter-long spittle bug —-about the size
of a pencil eraser-— is bigger and heavier than the
bloodsucking flea, yet still able to outjump its tiny rival
by accelerating faster. The spittle bug reaches its heights
by unleashing the large amount of stored energy in its
muscular hind legs. When it is not jumping, it uses its
smaller forelegs to move around while dragging its hind
legs, which are constantly poised for liftoff. During take-
off, the spittle bug accelerates at more than 400 times the
force of gravity compared to 135 times of a flea.
. . While feeding, the spittle bug covers itself in
bubbles of white, foamy saliva to protect from the sun and its enemies.
July 24, 03: Japan's Science Agency plans to request more
than $84 million for a research project into human proteins
that aims at unraveling the secrets of life. The goals are
to produce medicines that do not have side effects and to
better understand the mechanics of life, through studying
the interactions of some 20,000 to 30,000 proteins.
Scientists are only now beginning to understand the
complexity of the body's estimated 100,000 kinds of
proteins, which help to build tissue and regulate bodily functions.
July 2, 03: One of Nature's curiosities, the African dung
beetle, gets its remarkable sense of direction by using the
polarization of moonlight, the first time that this ability
has ever been spotted among animals.
. . Swedish and South African biologists say the
answer lies in a batch of the beetle's retinal cells which
are sensitive to polarised light. Light from the Sun
scatters into shimmering, polarized patterns, unseen to the
human eye, when it strikes tiny particles in the
atmosphere. In 2001, scientists discovered that moonlight,
even though it is a million times dimmer than sunlight, does the same.
. . S. zambesianus starts to forage on the wing for
fresh dung at around sunset, using the polarization
patterns formed by around the setting sun to figure out a
straight departure bearing, should it come across any food.
But after twilight, the solar cue is no longer available. The only light is lunar.
. . The researchers monitored the movements of the
beetles at night and found that the bugs went off in
straight lines away from the dungpile. This ability may
turn out to be widespread in the animal kingdom", the biologists say.
June 31, 03: Mandarin speakers use more areas of their
brains than people who speak English, scientists said, in a
finding that provides new insight into how the brain
processes language. Unlike English speakers, who use one
side of their brain to understand the language, scientists
at the Wellcome Trust research charity in Britain
discovered that both sides of the brain are used to
interpret variations in sounds in Mandarin. "We were very
surprised to discover that people who speak different sorts
of languages use their brains to decode speech in different
ways; it overturned some long-held theories."
June 23, 03: People who say they are sensitive to pain are
not just being big babies --they really do feel more pain,
researchers said. Brain images show that people who report
feeling more pain --in this case to heat-- also have more of a reaction in the brain.
June 20, 03: A giant sea spider the size of a dinner plate
and armored shrimps are just some of the new species
discovered by a marine expedition in deep water northwest
of New Zealand. They also photographed deep sea sponges and a prickly shark.
June 19, 03: The closest look yet at the Y chromosome --
which makes men different from women at the most basic
level-- shows it is not as puny as scientists believed. The
tiny chromosome in fact carries more genes than mainstream
wisdom had dictated. Most seem to be devoted to sperm
production. And the chromosome uses an unusual mechanism to
repair these genes when they become damaged. The chromosome
can form little loops in which the genes at one end can
press against the genes at the other end of the palindrome,
swapping sequences and thus repairing --or passing along-- mutations.
. . "Does analyzing the sequence of the Y chromosome
tell us why men are incapable of stopping to ask for
directions?" asked Dr. David Page, an investigator who led the study.
June 19, 03: Dolphins make clever changes to their sonar
signals as they home in on their prey, according to a study
published in the journal Nature. Operating in the dark,
bats, submarines and dolphins have to rely on sound rather
than vision, sending out high-frequency pings or "clicks" to locate their targets.
. . Bats resolve this problem by decreasing the
sensitivity of their hearing once they have emitted the
signal, and sub sonar operators do the same by turning down
the "gain" control on their receivers. Instead of turning
down their sonar receivers, dolphins adjust the volume on their transmitters.
June 19, 03: A comet collision with Earth around 55
million years ago may have kick-started a crucial early
phase of mammal evolution. The impact could have triggered
an ancient greenhouse warming thought to have encouraged
primitive mammals to disperse across the world and
diversify into three important groups still with us today.
. . These groups were the Artiodactyla, the
Perissodactyla and the Primates - the mammalian order that
includes humans. Modern Artiodactyls include sheep, pigs,
camels and giraffes. Today's Perissodactyls include horses, tapirs, rhinos and zebras.
. . Professor Kent and his team say the impact may
have been caused by an object measuring about 10 kilometers
across --about the size of Halley's Comet. They found tiny
iron-rich particles similar to those found in 65-million-
year-old sites associated with the comet or asteroid
collision that supposedly killed off the dinosaurs.
. . The Palaeocene-Eocene impact could have been a big
snowball containing little rock. This could account for a
relative absence in the Atlantic cores of iridium, an
element found abundantly in meteorites and in 65-million-
year-old clays. It is known from the composition of rocks
and marine sediments laid down at the Palaeocene-Eocene
boundary that global temperatures at the time rose by around 6 degrees Celsius in less than 1,000 years --an event known as the thermal maximum.
June 19, 03: Why are humans so hairless compared to other
primates? Theorists argue that early humans shed their fur
to aid cooling on the sun-baked savanna. Now, scientists
suggest that clothes, shelter, and fire allowed us to shed
our hair along with the ticks, fleas, and other
bloodsuckers that hide in it. Only a handful of the 5,000
or so mammals -—mostly semi-aquatic species such as whales,
walruses, and hippopotamuses—- are not covered in dense fur.
Dec 5, 01: (but I just ran across it) Modern humans left
Africa in several waves -—the first about 1.7 million years
ago, another between 800,000 and 400,000 years ago, and a
third between 150,000 and 80,000 years ago. The fossil record shows that about 100,000 years ago, several species of hominids populated Earth.
. . Homo sapiens could be found in Africa and the
Middle East; Homo erectus, as typified by Java Man and
Peking Man, occupied Southeast Asia and China; and
Neandertals roamed across Europe. By about 25,000 years
ago, the only hominid species that remained was Homo sapiens.
. . On two archaeological sites in Israel, people had
lived in the caves, at least occasionally, for more than
130,000 years. Most remarkable about the finds was the
discovery that the caves had changed hands between
Neandertals and modern humans no fewer than three times (4
occupations). "Neandertal populations [may have been]
driven south by rapid climate change around 75,000 years ago."
June 19, 03: An international team of researchers has
found that taking a longer time to reach adulthood is a
fairly recent development in human evolution. They have
concluded that it occurred sometime between 800,000 years
ago and the appearance of the larger-brained Neandertals
about 300,000 years ago -—a finding that surprised them.
"We expected it to have occurred much earlier, in Homo erectus."
June 18, 03: New genetic evidence that lineages of chimps
(currently Pan troglodytes) and humans (Homo sapiens)
diverged so recently that chimps should be reclassed as
Homo troglodytes. The move would make chimps full members
of our genus Homo, along with Neandertals, and all other
human-like fossil species. "We humans appear as only
slightly remodeled chimpanzee-like apes", says the study.
Geneticists have concluded that about 90 million years have
elapsed since all living primates shared their last common ancestor.
. . Within important sequence stretches of
these functionally significant genes, humans and chimps
share 99.4% identity.
June 15, 03: The "Mormon cricket" actually is a katydid, similar to a grasshopper.
. . Their voracious appetites take in anything —
sagebrush, alfalfa, wheat, barley, clover, seeds, grasses,
vegetables. At a density of just one cricket per square
yard, they can consume 38 pounds of forage per acre as they
pass through an area. They don't fly, but can hop and crawl
a mile in a day and up to 50 miles in a season. And before
they die in the fall, they lay the eggs that will become next year's swarm.
. . The chief weapon is carbaryl, an insecticide
commonly known as Sevin. It is mixed with bran and spread
before the crickets as they advance. Crickets lured to the
bait quickly die. The poisoned carcasses are consumed by
cannibalistic fellow crickets, which also die.
. . A 1939 state publication noted an infestation in
Eureka County in 1882, when trains were unable to travel
the main line of the Central Pacific Railroad "due to the
rails being so thoroughly greased with crushed crickets."
June 16, 03: The internal clock shared by all mammals is
reset each day by just three types of light-sensitive cells
—-rods and cones, known about since the 19th century, and a
third type of cell that produces a recently discovered
protein. The finding is as basic as it is controversial: Other scientists maintain the eyes include other types of light-sensitive cells as well.
. . The new study, done on mice, found that the cell
trio likely accounts for the entire ability of all mammals
to detect light. Beyond seeing, the eyes also track changes
in light levels to signal the body's clockwork adjustment
of everything from sleep patterns to blood pressure.
. . "Are there other light-detection systems in the
eye?" asks study co-author King-Wai Yau, of Johns Hopkins
University and the Howard Hughes Medical Institute.
"Essentially none. When you take these things out, that's it."
. . The study suggests that exposure to that blue-
green light may provide the most effective relief for
humans suffering from jet lag or seasonal affective disorder.
June 9, 03: Ancient oceans may have been split for nearly
2 billion years into two distinct layers that resemble
conditions in the modern Black Sea, able to support life
near the surface but almost devoid of life in deep water, a
new study suggests. They compared iron and sulfur
concentrations in terrestrial rock sample cores about 1.5 billion years old.
. . The key difference between the layers, according
to Harvard University researchers, was the level of oxygen
dissolved in the water. "It was maybe only a few percent of modern levels."
. . Scientists believe there was a major increase in
oxygen levels beginning about 2.4 billion years ago,
followed by a long stretch called the Proterozoic era
before oxygen levels started to rise again roughly 800
million years ago. That increase occurred just before the emergence of large animals and the explosion of great numbers of different species of all sizes.
June 9, 03: Bad news: A gene that triggers flowering in
wheat plants has been isolated for the first time, making
it possible for scientists to one day develop more
productive crops. A team of scientists at University of
California-Davis located the wheat gene that controls
vernalization, the process by which cold temperatures
prompt some plants to flower. The gene, called VRN1, could
later be manipulated so that farmers could grow region-
specific varieties of wheat better attuned to the climate
in which they grow for flowering at a particular time.
May 29, 03: A Panamanian government proposal to take legal
control of Coiba Island national park, known as the
country's "Galapagos", and develop it for tourism could
destroy one of Latin America's most precious ecological jewels, conservationists say. Coiba is home to animal, plant and bird species found nowhere else in the world.
. . The bill, which is being debated this week, could become law by mid-June.
May 26, 03: An island located halfway between Antarctica
and New Zealand was declared rat-free, some 200 years after
rats arrived there by sealing and whaling boats.
. . Campbell Island had the largest population density of rats
anywhere in the world. They had reduced the island's shearwater seabird
population to a handful "which will take hundreds of years to recover."
May 22, 03: A study of a common wild mouse in the Chicago
area suggests evolution can occur surprisingly fast, in
about 150 years. Because the evolutionary change coincides
with the urbanization of the Chicago area, the researchers
said humans may have changed the local environment,
spurring the high-speed evolution. Such fast evolutionary change has been shown in fruit flies, but this is the first time it's been shown to occur in mammals.
. . Tons of rat poison pellets were dumped on the
uninhabited 27,900-acre island, 440 miles south of New
Zealand, by helicopter two years ago to kill the Norway rat.
May 19, 03: Chimpanzees are more closely related to people
than to gorillas or other primates and probably should be
included in the human branch of the family tree, a research team says.
. . Currently, humans are alone in the genus Homo. But
Goodman argues, "We humans appear as only slightly
remodeled chimpanzee-like apes." He says humans and chimps
share 99.4% of their DNA, the molecule that codes for life.
. . Chimpanzees are in the genus Pan along with bonobos, or pygmy chimpanzees.
Goodman's proposal would establish three species under Homo. One would be Homo (Homo) sapiens, or humans; the second would be Homo (Pan) troglodytes, or common
chimpanzees, and the third would be Homo (Pan) paniscus, or
bonobo chimpanzees. We shared a common ancestor about 7 million years ago. No one is arguing today to put chimps and gorillas in the same genus.
. . Tracking mutation rates in the genes, the
scientists estimate that the common ancestor of chimps and
humans diverged from gorillas about 7 million years ago,
and then separated into two species between 5 million and 6 million years ago.
May 14, 03: Commercial fishing has emptied the world's
oceans of 90% of the populations of large prized
tuna, swordfish, marlin and other fish species that
flourished a half-century ago, two marine scientists reported.
. . The new research based on nearly 50 years of data
offers a bleak outlook for some of the most commercially
valuable trophy fish species and further debunks a notion
that oceans are limitless blue frontiers teeming with boundless life.
. . It generally takes less than 15 years for giant
commercial fishing operations to kill 80% of a new fishing ground's abundance.
May 13, 03: A rare freshwater dolphin found only in
China's huge Yangtze River could die out within the next 10
years unless fishing methods there change, the World
Conservation Union said. It could quickly be followed into
extinction by the vaquita porpoise of Mexico's Gulf of
California, New Zealand's Hector's dolphin, and several populations of whales.
May 12, 03: Scientists have discovered the same genetic
mutation in 11 types of West Nile- and malaria-spreading
mosquitoes — a mutation that may explain their growing
immunity to insecticides. The findings could give chemical
companies a molecular target for new insecticides to combat
mosquitoes no longer kept in check by existing chemicals.
. . They also found it in resistant populations of the
Anopheles gambiae mosquito —-which transmits the malaria
parasite. The same mutation may also be present in other
insect pests, including those that eat crops.
. . Although malaria is primarily a problem in Africa and the developing world, a wild reservoir of the parasite was found last year in Virginia.
May 9, 03: Scientists said they have discovered the
world's smallest seahorse, after realizing it was not
simply the offspring of a species they already knew about.
The pygmy seahorse averages .64 inch in size, smaller than
a fingernail, and lives in coral in the tropical waters of the western Pacific.
. . Before this discovery, there were 32 known species
of seahorses, but some scientists believe there could be as many as 50.
May 7, 03: Researchers have found two species of beetle to
be a potent weapon in Africa's fight against water
hyacinths, an aquatic plant that was introduced from Brazil in the 19th century by misguided horticulturalists and has become a devastating superweed.
May 7, 03: A new species of jellyfish with a yard-wide
fleshy red bell and a cluster of wrinkled, thick arms has been found by scientists nearly a mile beneath the cold, dark waters of the Pacific Ocean.
May 5, 03: The shrinking woollen cardigan may become a
thing of the past, after Australian scientists announced
they have found a way to breed sheep with near shrink
resistant wool. They have identified the genetic link. The
discovery should allow wool growers to identify and select
sheep which naturally produce low-shrinkage wool.
. . A geneticist of Western Australia's Department of
Agriculture put more than 2,000 wool samples into the wash.
"The samples come out as a nice round ball, the smaller the
ball, the greater the felting." They'll breed sheep wose
wool has the least. . Also: "As with felting, woolgrowers in areas where dust is a problem, can breed sheep with a stronger resistance to dust content."
Apr 29, 03: Birds that migrate seem to have better long-
term memories than ones that don't find their way back to
the same place year after year. In what they say may be the
first scientific evidence that memory duration is related
to migration, a team of German researchers tested the idea.
Apr 25, 03: A collection of South African humanoid fossils
is far older than previously thought, and may represent the
oldest direct link to humanity. Remains from the world's
richest hominid fossil site, the nearby Sterkfontein caves,
were more than four million years old. The new dates put
the fossils on a par with specimens from the same
Australopithecus group of species found in northern Kenya
as humanity's oldest direct ancestors, and make them almost
a million years older than scientists previously thought.
. . The painstaking new technique, developed with the
help of researchers at Purdue University, Indiana, in the
United States, measures the amounts of nuclear isotopes of
aluminum and beryllium in material surrounding the specimen.
Apr 22, 03: Thousands of Australian mammals, reptiles and
bird species face extinction as landclearing gains pace,
according to a leaked government report. 1.236 million
acres of the vast island continent, home to some of the
least populated areas in the world, was lost to land-clearing every year.
Apr 10, 03: Cannibalism may have spread a deadly brain-
wasting disease among human populations thousands of years
ago --and may have eventually helped people evolve a
resistance to such diseases, researchers reported.
Anthropologists debate whether prehistoric humans ate one
another, but Collinge and colleagues, reporting in the
journal Science, say they have new evidence they did.
. . Genetic studies show that humans around the world
have a similar predisposition to resist the brain-
destroying disease called Creutzfeldt-Jakob disease. CJD
occurs naturally in about one in a million people. It is incurable and always fatal, chewing holes in the brain that lead to dementia and death.
. . A closely related disease called kuru was once
common in Stone Age populations in Papua New Guinea in the
first half of the 1900s, and was closely linked to the
practice of eating the dead in rituals.
. . Sheep have their own version of the disease called
scrapie, and it passed into British cattle herds. CJD, BSE
and related diseases are all caused by a crumpled protein
called a prion. They have also found that some people have
a genetic predisposition to prion diseases, but many have a genetic resistance.
. . They got blood samples from Kuru women over the
age of 50 and did genetic analysis. They found a genetic
mutation known to protect against prion disease was much
more common in these women, who would have survived despite
being cannibals, versus the living population of younger Kuru people.
. . The evidence suggests the genetic mutations date
back 500,000 years, they said.
Apr 18, 03: Signs carved into 8,600-year-old tortoise
shells found in China may be the earliest written words,
say archaeologists. The symbols were written down in the
late Stone Age, or Neolithic Age. They predate the earliest
recorded writings from Mesopotamia - in what is now Iraq --
by more than 2,000 years. The archaeologists say they bear
similarities to written characters used thousands of years
later during the Shang dynasty, which lasted from 1700-1100 BC.
The European eagle owl --20 inches tall, a 6-foot wingspan-- is the world's largest species of owl.
Apr 14, 03: Chinese scientists have discovered a gene that
regulates the branching and height of rice plants, hinting
at a way to boost yields of a crop that feeds more than
half the world's population. The researchers showed that
inserting extra copies of the gene into rice plants
increased the number of seed-bearing sprouts called
tillers. The gene appears to be a "master switch" that
regulates proteins that control a number of features of rice.
Apr 13, 03: Scientists have completed the finished
sequence of the human genome, or genetic blueprint of life,
which holds the keys to transforming medicine and
understanding disease. "It's a bit like moving on from a first attempt demo music tape to a classic CD." The rough draft was announced in June 2000.
. . It's already aided scientists in discovering a
mutation that causes a deadly type of skin cancer and
accelerated the search for genes involved in diabetes,
leukemia and childhood eczema. The completed sequence will
help scientists to identify the 25,000-30,000 genes in
humans, including those involved in complex diseases such as cancer and diabetes.
. . There are far fewer genes than scientists had
expected and proteins, which build tissues and regulate the
body's function, are much more complex than they thought.
"The nematode worm has about 17,000 genes, so we haven't
really got very many more than a small worm."
Apr 2, 03: Coots, common marsh birds not renowned for
their intelligence, can count, scientists said. Female
coots can recognize and keep track of their eggs, even when
eggs from other birds are present in the nest. "The ability
of females to count only their own eggs in a mixture of eggs is a remarkable feat that provides a convincing, rare example of counting in a wild animal."
Apr 2, 03: Tooth marks in bones from a 30-foot-long
dinosaur that roamed Madagascar over 65 million years ago
are clear evidence it was a cannibal, because the size,
spacing and serrations match the blade-like teeth of the species.
Mar 30, 03: Portuguese scientists have found traces of the
presence of the Iberian lynx, which had been believed to be
extinct in Portugal, by analyzing the DNA in excrement
found in Alentejo, south of Lisbon. A search in 2002 found
no trace of the Iberian lynx in Portugal, whose numbers are
estimated at less than 200 worldwide. It's one of the three
species most threatened with extinction, on the red list
published by the International Union for Nature
Conservation. The population, which lives chiefly in wooded
areas and scrubland, has halved in 10 years because of the
destruction and loss of its habitat. It has also fallen
victim to the introduction of myxomatosis to control rabbits, its main prey.
Mar 30, 03: Killer mites are decimating Germany's colonies
of bees and honey production is expected to fall sharply.
The microscopic varroa mite is the killer bug responsible
for wiping out 40% of Germnay's one million bee
colonies and honey production this year is expected to fall
to 15,000 tons from 25,000 tons in 2002. [HEY; that's
four or five times a mere decimation.]
. . Fears are also growing that there might not be
enough bees to help pollinate the country's fruit trees and bushes.
Homo heidelbergensis, which dominated Europe around
600,000-200,000 years ago, is thought to have given rise to
both the Neandertals and modern humans.
Mar 26, 03: Neandertals were not the ham-fisted cavemen
often portrayed in cartoons, but instead had at least as
much dexterity as modern humans, computer modeling of
ancient hand bones shows. The modeling suggests that the
disappearance of Neanderthals cannot be attributed solely
to a physical inability to make tools as successfully as
their modern human cousins, researchers said. Neanderthal
hands were more heavily muscled than modern human hands, with broad finger tips.
. . The oldest fossils attributed to Neanderthals are
more than 350,000 years old.
"Man of the Neander Valley"
Lived: 230,000-22,000 years ago.
Range: Europe, Central Asia, Middle East.
Diet: Relied heavily on meat.
Size: Male: 166cm / 77kg F: 154cm / 66kg.
Brain Size: 12% larger than a modern brain.
Mar 12, 03: Scientists in Italy said they have uncovered
what are thought to be the oldest footprints of primitive
humans. The fossilized hand and footprints belong to three
early humans who were probably climbing down the side of
the Roccamonfina volcano in southern Italy about 385,000 to
325,000 years ago. The 3 sets of prints, embedded in
fossilized volcanic ash, are about 8 inches long and 4
inches wide, and belonged to primitive humans who were about 4 feet, 11 inches tall.
. . Older footprints of hominids --made by more
distant ancestors-- date back 3.5 million years and were
found in petrified volcanic ash at Laetoli in northern Tanzania.
March 10, 03 — A 5,100- to 5,350-year-old wooden wheel
recently was found in Slovenia buried within an ancient
marsh. The wheel is surprisingly technologically advanced.
Made of ash and oak woods, the wheel has a 27.5-inch radius
and is nearly two inches thick. An axle, approximately four feet long, also was found.
. . The true beginnings of the wheel could date back
to the Paleolithic era (15,000-750,000 years ago). While
the location of the wheel's earliest inception remains
unknown, general consensus places its invention in Mesopotamia.
Javanese Homo erectus populations living 25,000 to 50,000
years ago were quite isolated and had very little to do
with the ancestry of modern humans.
Mar 10, 03: A new study reports on the exaggerated anatomy
of the male Argentine lake duck, whose penis is about the
same length as its body. The case is especially intriguing
because very few species of birds have penises. Its unusual
anatomy may be related to strong competition in mating and reproduction.
. . Researchers from the University of Alaska
discovered that the penis of Oxyura vittata, when fully
extended, is about 0.5 meters long. When not in use, the
corkscrew-shaped penis retracts into the duck's abdomen.
. . The duck is small, weighing 640 grams (a little
more than a pound) and extending about 41 cm (16") long
from head to tail. Its penis, at about 43.5 cm (17"), is
the longest of any bird known so far. The bird is extremely clumsy on land.
. . The base of the duck's penis is covered with
coarse spines, while the tip is soft and brush-like. The
researchers think a drake may use the brush-like tip as a
sort of cleansing instrument before ejaculation to remove
sperm in the females oviduct that was deposited by another
suitor, thus increasing the mating drake's chances of
paternity. Similar sperm-removal behavior has also been
seen in some fish and insect species. Stiff-tail ducks are
promiscuous, they said, and Argentine lake ducks are particularly so.
Mar 10, 03: Scientists have discovered a species of
brittle star whose outer skeleton is covered with
crystalline lenses that appear to work collectively as an all-seeing eye.
. . "These lenses have exceptional optical
performance", said the co-author of a report on the
discovery published in Nature. "They are compensated for
physical effects that bother us when we fabricate lenses in
the laboratory" —effects known as birefringence and
spherical aberration. Each of the bones is a single calcite
crystal and each window is in the shape of a double lens.
. . Although it's yet to be proven, the whole
photoreceptive system is thought to function like a
compound eye, allowing brittle stars to detect predators
and seek out hiding places. "Thanks to evolution, they have beautifully designed crystal lenses that are an integral part of their calcite skeleton."
Mar 10, 03: Scientists have discovered a long-armed
octopus that mimics poisonous creatures of the sea to avoid
its predators. The clever creature is a brown octopus about
60 cm long that slithers along the muddy bottom of shallow,
tropical estuaries where rivers spill into the sea. It was
discovered so recently that it still doesn't have a
scientific name, but scientists are intrigued by its
uncanny ability to impersonate lion fish, soles, and banded sea snakes.
Octopuses are thought to be one of the most intelligent
invertebrates and can change the color and texture of their
skin to blend in with rocks, algae, or coral to avoid
predators. But until now, an octopus with the ability to
actually assume the appearance of another animal had never been observed.
. . Mimicry is a fairly common survival strategy in nature.
Certain flies, for example, assume the black and yellow
stripes of bees as a warning to potential predators. But
the adaptable octopus is the first known species that can assume multiple guises.
it lives in a habitat that's not very appealing to scuba
divers—a muddy and relatively barren landscape that lacks
the variety and splendor of life found in coral reefs.
"We also think that is why it has such a dramatic
[mimicking ability]", said Tregenza. "It has nowhere to hide.
Tregenza said the octopus may decide which creature to
impersonate depending on what particular predator is near.
May 2, 01: Dolphins recognize themselves in mirrors —one of the few mammals other than humans that have the ability to do so. Previously, it was thought that only the great apes could, & maybe only Humans and Chimps among those.
Mar 6, 03: Richard G. Klein of Stanford University said
modern studies of mitochondrial DNA from Neanderthal
fossils suggest that the modern humans and the Neanderthals
had a common ancestor about 500,000 years ago. But he said
the studies do not support the notion that there was
interbreeding after modern humans evolved in Africa and
invaded Neanderthal habitats, starting about 45,000 years ago.
. . He said modern humans may have evolved a gene
promoting speech and language that the Neanderthals lacked,
but this is a theory without substantial proof.
Mar 4, 03: The world is more mobile, "fast and furiously"
transporting exotic products, animals and bugs from
continent to continent. As a result, there is an increased
chance of spreading more mosquito-borne diseases such as
yellow fever, dengue fever, malaria, encephalitis and Rift
Valley fever —-a virus transmitted from livestock to humans
by mosquitoes that causes diarrhea, internal bleeding and can result in death.
Feb 27, 03; Fifty years to the day from the discovery of
the structure of DNA, one of its co-discoverers has caused
a storm by suggesting that stupidity is a genetic disease that should be cured.
. . In a new documentary series to be screened in the
UK on Channel 4, Watson says that low intelligence is an
inherited disorder and that molecular biologists have a
duty to devise gene therapies or screening tests to tackle stupidity.
. . "If you are really stupid, I would call that a
disease", says Watson. "The lower 10 per cent who really
have difficulty, even in elementary school, what's the
cause of it? A lot of people would like to say, 'Well,
poverty, things like that.' It probably isn't. So I'd like
to get rid of that, to help the lower 10 per cent."
. . Watson, no stranger to controversy, also suggests
that genes influencing beauty could also be engineered.
"People say it would be terrible if we made all girls
pretty. I think it would be great."
. . Watson's views may emanate from his own family's
experiences with his son, who has a mental illness resembling schizophrenia.
Feb 28, 03: An infestation of ants which is attacking
numerous animal species in Australia is threatening to
spread across the country, scientists have warned.
. . Described as one of the world's most vicious species of
ant, the Yellow Crazy Ant sprays formic acid into the eyes
of other animals, leaving them vulnerable to attack and
unable to feed themselves. The ants' victims died, not from
the attack, but from starvation, because they were blind.
. . They're one-centimeter long, originally from
India. & were so named because of their erratic behavior
when a nest is disturbed.
. . The ants have already wiped out up to 20 million
red crabs, as well as birds and other animals on
Australia's Christmas Island in the Indian Ocean since
1989, and have since spread to 63 locations in the Northern Territory on the mainland.
. . Yellow Crazy Ants form multi-queened "super-colonies" in which foraging worker ants reach around 1,000 per square meter or 79 million per hectare of bush. Once a super-colony is established, it can expand rapidly, growing around its edges by some three meters per day or one kilometer a year.
Feb 26, 03: Not all ants live up to their image as egalitarian hard workers --some are even guilty of nepotism, Finnish researchers said. Instead of putting the
best interests of the colony ahead of their own, scientists
at the University of Helsinki have discovered an ant
species that ruthlessly favors its own relations in
colonies descended from multiple queen ants. Worker ants in
the species favored their own relatives when caring for eggs and larvae, which researchers said implied they capitalized on their ability to discriminate.
. . "This nepotistic behavior indicates that ant
workers are able not only to detect kin relationships, but also to pursue their selfish genetic interests if the costs to their colony are not prohibitive."
In the taxonomy of living creatures, the highest categories, kingdoms and phyla, capture the most general features of a very large group of organisms. The phylum of
vertebrates, for instance, includes fish, birds, and
mammals. There are 32 phyla today, all dating back to the
post-Cambrian period. Evidence suggests, however, that as many as a hundred phyla may have existed during the Cambrian itself, most of which quickly became extinct.
. . These phyla are thought to have been established
by the first species to emerge — hence "top down." These radically different creatures then branched into daughter species, slightly more similar to one another but still
distinctive enough to become founders of the next category
in the hierarchy, classes. The process replicated itself to produce daughter species somewhat more similar to one another which in their turn founded orders. Next were
families, and finally genera. The pattern is one of
explosive differences among the species that branch early
in the process, with progressively less dramatic variation in successive branchings.
. . Where this effect applies, all species keep changing in a never-ending race simply to sustain their current level of fitness. Chaos prevails.
Thousands of calcite crystals are spread throughout the body of the brittlestar, a marine invertebrate, collectively forming a curious kind of eye for the animal.
These micro-lenses naturally compensate for two types of
distortions common in lenses: bi-refringence and spherical aberration.
Feb 24, 03: A common octopus in a German zoo has learned to open jars of shrimp by watching zoo attendants perform the act underwater. Frida, a 5-month-old female octopus, opens the jars by pressing her body on the lid and grasping
the sides with the suckers on her eight tentacles. With a
succession of body twists, she unscrews the lid.
Feb 22, 03: Male king penguins store undigested food in their stomachs for up to three weeks. The talent is unique among higher vertebrates and ensures a constant supply of
food for their chicks. But how they do it was a mystery.
Now an analysis of the birds' stomach contents shows the
penguins keep food fresh by destroying bacteria in their stomachs, suggesting that they produce an antibacterial agent in their digestive tracts.
There are ant-eating squirrels in Southeast Asia. There's
a mouse-sized pygmy squirrel in Gabon. the earliest
squirrel was in North America. Squirrels diverged into five major branches.
Feb 14, 03: a "supertaster" --a group classified by a scientist as being so sensitive to bitter tasting foods that they want to spit them out. Bitter foods include
coffee, chocolate and dark green vegetables.
. . Supertasters live in a "neon taste world" roughly three times as intense as the "pastel world" of non-tasters. About one-quarter of the population is made up of supertasters. Extreme supertasters represent only about 10 to 15% of the population, she said.
Feb 21, 03 - Peruvian geologists have discovered the most complete horse fossil in the Americas. It did died out some 10,000 years ago. It became extinct about 10,000 years ago; again, around the same time humans settled South America.
Feb 19, 03: A mysterious self-cloning female crayfish, popular with German aquarium owners, could pose a threat to native European species if it were released into the wild, scientists say. It can reproduce without mating:
Parthenogenesis --a form of self-cloning, is found in
creatures such as snails and water fleas but is unusual in crayfish.
. . The Marmorkrebs' ability to produce 20 or more clones of itself in six months could be a danger and a competitor to crayfish in the wild.
Feb 19, 03: Australia's oldest human remains are 20,000 years younger than scientists had previously thought, researchers said, in a finding that sheds new light on when
early humans colonized the continent.
. . Instead of being 62,000 years old, the remains found near Lake Mungo in southeast Australia are 40,000 years old. The age of the skeleton is important because if the remains are younger than previously expected they fit
in better with the "out of Africa" theory, which suggests
early humans migrated from Africa to other parts of the globe.
. . Artifacts found below the level of the burial date to about 50,000 years ago.
Feb 12, 03: Scientists for the first time have identified
a common genetic mutation in people over 100 years old, a
finding they say could be a key to discovering a way to avoid the ravages of aging.
. . In a study conducted at the California Institute
of Technology in Pasadena, California, researchers found that centenarians were five times more likely than others to have the same mutation in their mitochrondrial DNA.
. . Mitochondrial DNA, the portion of DNA located in
the mitochondria or "powerhouses" of the cell, passes only
from the mother to offspring. The mitochondria capture the
energy released from the oxidation of metabolites and
convert it into energy. "It is possible that in the process of replication, these molecules are less damaged by oxidation, but we don't know that yet."
Feb 12, 03: Madagascar's carnivorous mammals, which are
found nowhere else in the world, are descendants of a
mongoose-like creature that floated to the island from
Africa on a raft of vegetation about 21 million years ago, scientists said.
. . Because there are few fossil records of
Madagascar's land mammals, determining how, when and from where the creatures came from has been one of the great unsolved mysteries of natural history. One theory was that
the carnivora, an evolutionary order of mammals that
includes dogs, cats, bears and pandas, were already on
Madagascar when it separated from the African continent 165
millions years ago. Another hypothesis suggested the
mammals traveled over a land bridge from Africa about 45 to 26 million years ago.
. . But new DNA research by scientists from Yale
University in Connecticut and The Field Museum in Illinois suggests neither theory is correct and that the so-called sweepstakes model of dispersal is the most probable.
. . "In fact, all 100 or so known species of
terrestrial mammals native to Madagascar, which fall in four orders --carnivorans, lemurs, tenrecs and rodents-- can now be explained by only four colonization events."
Feb 11, 03: Photosynthesis and nitrogen fixation: there
could be a kinship between these two world-altering
chemical processes in Earth’s early biosphere. They may be
related to each other because some of their key enzymes
appear to have evolved from a common ancestor that might be
part of a third, significantly different, biochemical process.
. . A critical part of the emerging evolutionary
picture seems to be "horizontal gene transfer" –-genetic
change that occurs by the exchange of genetic material
between bacteria. This process allows for sudden evolutionary leaps that are perhaps not possible through gradual genetic change and natural selection.
Jan 24, 03: Bugs don't have lungs, so how do they breathe?
Maybe more efficiently than people, according to the first
close-up view of insects forcing air in and out of tiny
oxygen pipes.
. . It took one of the world's strongest X-ray beams —
a view hundreds of times more detailed than today's most
sophisticated medical scans can provide — for scientists at
The Field Museum in Chicago and Argonne National Laboratory
to videotape how beetles, crickets and ants breathe. While
resting, the insects exchanged up to half the air inside
their main oxygen tubes every second — equivalent to how
hard a person breathes while doing moderate exercise, the
researchers report in Friday's edition of the journal Science.
. . These tubes, called tracheae, connect to tiny air
holes in the insect's outer coating. For decades,
scientists thought air just passively oozed into those
holes. Then researchers spotted some tiny air sacs near
insects' wings, legs and abdomens that they might use to help pump air inside.
. . But the rest of the insect body is rigid, so no
one thought much more air pumping could go on. Instead,
Westneat discovered insects somehow squeeze the air tubes
throughout their bodies to suck air in and out, much as lungs do.
Future research ranges from how bugs eat, to how beetles' eight-to-10 hearts function.
Jan 24, 03: Scientists do not understand why cleft palate
and other craniofacial birth defects occur. Understanding
what causes a beak to develop the way it does could in turn
shed light on human craniofacial development.
. . At the University of California, San Francisco,
they took 36-hour-old duck and quail embryos from an
incubator and drilled small holes in the eggs encasing
them. Using the tiniest of needles, Schneider sucked out
the cells that seemed to give rise to beaks, called neural
crest cells, from duck embryos and replaced them with
neural crest cells from quail embryos, and vice versa.
. . Sure enough, the ducks grew pointy little quail
beaks and the quails grew that distinctive flat, wide duck bill.
Jan 22, 03: Scientists in China have found the fossils of
a feathered creature, identified as a small dinosaur, that
they say casts new light on the origin of birds and their
ability to fly. With two sets of wings, one on the
forelimbs and the other on its legs, it was a strange-
looking animal, something like a scaled-up, three-foot-
long dragon fly, but with feathers. All four of its wings
were covered with feathers that appear to have been
arranged in a pattern similar to modern birds. Even its
long tail was fringed in feathers.
. . In the journal Nature, the Chinese paleontologists
said the animal probably used its four wings to glide from
tree to tree, much as flying squirrels do today. This
represented, they said, a previously unknown intermediate
stage in the evolution of birds and flight. Dr. Xu's team
noted that the presence of feathers on the legs would be a
hindrance to running fast. It thus "provides negative
evidence for the ground-up hypothesis."
. . Dr. Prum cautioned that "substantial questions
remain" concerning how the fossil animal used its four
wings and whether it had the shoulder and wing anatomy to
sustain powered flight. Dr. Xu said the new fossils
represented a distinct species of the small predatory
dinosaurs known as dromaeosaurs. It has been given the name Microraptor gui.
. . The clear outlines of four feathered wings, the
Chinese scientists said, were found in all six specimens of
the species. Each individual was about three feet long from
head to the tip of its long tail, but its body was no
larger than a pigeon's. The asymmetry of the feather vanes
is a characteristic of both sets of wings, the Chinese
group said. The pattern has long been recognized as
indicating aerodynamic function in flight or gliding.
Jan 22, 03: In what scientists believe may be the first
example of an animal taking a natural drug during
pregnancy, researchers from Japan's Kyoto University have
noticed that the sifaka, a type of lemur, eats plants
containing poisonous tannins before giving birth. Small
amounts of tannins are known to stimulate milk production
and veterinarians use them to prevent miscarriage. "This
makes them the first animal known to self-medicate when
pregnant", according to New Scientist magazine.
. . Michael Huffman, a primate expert at the
university, said pregnant females observed in Madagascar
ate more tannin-rich plants than other males or females.
"Some 39 species have been observed eating soil, which
soaks up toxins in the gut and allows the animals to eat
poisonous plants without getting sick", according to the magazine.
. . Chimpanzees also swallow leaves whole to induce
diarrhea to get rid of tapeworms and other parasites.
It is widely thought that the number of times a cell can
divide --and thus reinvigorate tissue-- is controlled by
the length of a microscopic structure called a telomere.
These structures are found on the end of our chromosomes
and in effect stop them from unravelling, acting in the
same way as the shiny bit at the end of the bootlace.
However, they get shorter each time a human cell
duplicates. At a certain length, the cell stops duplicating altogether.
Jan 20, 03: Scorpions don't bother to waste venom killing
a victim if they don't have to. Instead, they use a
prevenom that causes extreme pain, resorting to the
deadlier version only when necessary, researchers have
discovered. It's a clever strategy, Hammock explained,
because the deadly true venom uses a lot of proteins and
peptides that are costly for the scorpion to make. So
instead it tries to get by with a faster acting and more
painful toxin that doesn't kill, but is easier to make.
Jan 18, 03: Researchers on the southern Greek island of
Crete have unearthed 7 million-year-old remains: the
fossilized tusk, teeth and bones of a fearsome Deinotherium
Gigantisimum, the biggest elephant-like creature --nearly 15 feet tall.
. . A large hole in the middle of it's skull —-the
nasal cavity above its trunk-— could have given rise to the
tales of the cyclops, the ferocious mythological giant with
one eye that appears in Homer's "Odyssey" and other stories.
Jan 16, 03: Flapping their wings can help birds scoot up
steep hills and even defy gravity without taking to the
air, an expert in bird flight reports in the journal Science.
. . Dinosaurs with feathered forelimbs that had not
yet evolved into wings probably used similar mechanisms,
said Kenneth Dial of the avian flight laboratory at the
University of Minnesota. He proposes that such creatures
eventually evolved into birds. "It turns out the proto-
wings -- precursors to wings birds have today -- actually
acted more like a spoiler on the back of a race car to keep
the animal sure-footed even while climbing up nearly
vertical surfaces" Dial said in a statement. "In the proto-
bird, this behavior would have represented the intermediate
stage in the development of flight-capable, aerodynamic wings."
Jan 16, 03: New fish varieties genetically engineered in
laboratories to grow faster and larger should be kept off
the market until the Food and Drug Administration addresses
their potential threat to wild species, a private research group said.
. . The Pew Initiative on Food and Biotechnology
questioned the adequacy of FDA regulations in assessing the
risks of such transgenic fish escaping pens and taking over
the habitat of nongenetically engineered varieties.
Jan 10, 03: Tight genes help a nuclear waste-munching
bacterium resist the deadly effects of radiation, Israeli
and U.S. scientists reported. The DNA of Deinococcus
radiodurans, which can also survive extreme cold and
dryness, is tightly packed into a circle, the researchers
report in the journal Science. That dense ring helps keep
damaged DNA in place, allowing broken-off pieces to move
eventually back into position.
. . It can withstand 1.5 million rads, a measure of
radiation, which is 1,000 times more than any other life
form. Its existence suggests that life, in the form of
bacteria, could have survived in space and may thrive on other planets.
The quirks of humanity in fact have a common thread: they
are largely the result of natural selection acting to
maximize dietary quality and foraging efficiency. Changes
in food availability over time, it seems, strongly
influenced our hominid ancestors. Thus, in an evolutionary
sense, we are very much what we ate.
. . It's argued that the prevalence in modern
societies of many chronic diseases--obesity, hypertension,
coronary heart disease and diabetes, among them--is the
consequence of a mismatch between modern dietary patterns
and the type of diet that our species evolved to eat as
prehistoric hunter-gatherers.
. . The modern human brain accounts for 10 to 12
percent more of the body's resting energy requirements than
the average australopithecine brain did.
What is striking about human bipedal movement is that it
is notably more economical than quadrupedal locomotion at
walking rates. Knuckle walking spends some 35% more calories.
. . Australopithecines never became much brainier than
living apes, showing only a modest increase in brain size,
from around 400 cubic centimeters four million years ago to
500 cubic centimeters two million years later. Homo brain
sizes, in contrast, ballooned from 600 ccs in H. habilis
some two million years ago up to 900 ccs in early H.
erectus just 300,000 years later.
. . What is extraordinary about our large brain is how
much energy it consumes-- roughly 16 times as much as
muscle tissue per unit weight. (& time) At rest, brain
metabolism accounts for a whopping 20 to 25% of an
adult human's energy needs-- far more than the 8 to 10
percent observed in nonhuman primates, and more still than
the 3 to 5% allotted to the brain by other mammals.
. . Calculations suggest that a typical, 80- to 85-
pound australopithecine with a brain size of 450 cubic
centimeters would have devoted about 11% of its
resting energy to the brain. For its part, H. erectus,
which weighed in at 125 to 130 pounds and had a brain size
of some 900 cubic centimeters, would have earmarked about
17% of its resting energy-- that is, about 260 out
of 1,500 kilocalories a day--for the organ.
. . According to recent analyses by Loren Cordain of
Colorado State University, contemporary hunter-gatherers
derive, on average, 40 to 60% of their dietary
energy from animal foods (meat, milk and other products).
Modern chimps, in comparison, obtain only 5 to 7% of
their calories from these comestibles.
. . 3.5 ounces of meat provides upward of 200 kilocalories.
But the same amount of fruit provides only 50 to 100
kilocalories. And a comparable serving of foliage yields
just 10 to 20 kilocalories. It stands to reason, then, that
for early Homo, acquiring more gray matter meant seeking
out more of the energy-dense fare. [So big brains moved us toward carnivorism.]
. . The continued desiccation of the African landscape
limited the amount and variety of edible plant foods
available to hominids. Those on the line leading to the
robust australopithecines coped with this problem
morphologically, evolving anatomical specializations that
enabled them to subsist on more widely available, difficult-
to-chew foods. Homo took a different path. As it turns out,
the spread of grasslands also led to an increase in the
relative abundance of grazing mammals such as antelope and gazelle.
. . It seems that the first appearance of H. erectus
and its initial spread from Africa were almost simultaneous.
. . A 160-pound American male with a typical urban way
of life requires about 2,600 kilocalories a day, a
diminutive, 125- pound Evenki man needs more than 3,000
kilocalories a day to sustain himself. Using these modern
northern populations as benchmarks, Mark Sorensen of
Northwestern University and I have estimated that Neandertals most likely would have required as many as 4,000 kilocalories a day to survive.
Dec 8, 02: The first animal life didn't form until the
Cambrian Explosion 600 million years ago. Intelligent life -
-which we broadly define as human civilizatiion-- didn't
develop until a few tens of thousands of years ago.
. . "It might be argued that among mammals, humans
developed intelligence first and are thereby effectively
precluding the development of intelligence in any other
species", says McKay. "It follows from this argument that
intelligence evolves once and only once on a planet,
because once evolved, it changes the rules of the
interaction between species and effectively dominates the planet from then on."
. . Human intelligence may never have developed if the
dinosaurs had not gone extinct.
. . "One might speculate that perhaps Stenonychosaurus
(also known as Troodon) or her progeny did build radio
telescopes but their civilization was destroyed by some
internal or external catastrophe.
. . "For us to be the ONLY intelligent radio builders
in the galaxy, the odds would have much lower --about 1 in
million." The "Drake Equation" was formulated in 1961.
Dec 9, 02: Natives of India's Andaman Islands, once famed
for their ferocity and unique appearance, are indeed
genetically separate and may be direct descendants of Stone
Age settlers, researchers said. Analysis of DNA from
samples taken in recent times and 100 years ago show the
Andaman islanders, which include a group known as the
Jarawa, are genetically different from other Asians.
. . The Andamese peoples separated from other Asians
tens of thousands of years ago. While more closely related
to other Asians than to modern-day Africans, their DNA
suggests they may have descended from an earlier group of
people who left Africa and populated Europe and Asia.
Cetaceans, ruminants, and hippos share a common ancestor
not shared by any other mammalian group. The implication is
that a cow is more closely related to a dolphin or whale than to a pig or horse.
Dec 4, 02: The genetic blueprint of the mouse published
today shows there isn't much difference between mice and
men. Although the mouse is about 14% smaller than
the human genome, about 40% of the two genomes can
be directly aligned with each other. Both have about 30,000
genes and share the bulk of them, while 90% of genes
linked to diseases in humans are similar to those in mice.
. . "We share 99% of our genes with mice, and
we even have the genes that could make a tail", said Dr
Jane Rogers, of the Wellcome Trust Sanger Institute in Cambridge, England. Both mice and men shared a common ancestor, a creator about the size of a small rat, that lived during the time of the dinosaurs between 75 and 125 million years ago.
. . It is regarded as the most important scientific
breakthrough since the sequencing of the human genome.
Dec 3, 02: Scientists made a genetically engineered rice
that is more tolerant to drought and salty soil and is
highly productive. A team of researchers fused two E. coli
genes together and introduced them in the genetic makeup of
rice to make trehalose —-a sugar that can help plants survive during drought. So-called resurrection plants that grow in the desert can produce the sugar.
. . The trehalose genes can also be activated when the
genetically modified plants are exposed to low temperatures. The scientists said the technology could be used in corn, wheat and other crops.
11-02: Bio-researchers noticed that intestinal bacterial
communities grow and diversify just as the newborn's
intestinal blood vessels mature into a complex network.
This made them suspect that the microbes could play a
fundamental role in intestinal development.
. . To find out, the team examined the development of
intestinal-wall blood vessels in both normal and bacteria-
free mice. Gordon determined that the normal mice harbored
an extensive web of blood vessels, but germ-free mice had
only stunted, immature capillaries. However, if the germ-
free mice received a dose of gut bacteria while they were still young, blood-vessel development restarted immediately and finished in just 10 days.
Nov 21, 02: The pioneer scientist who helped crack the
human genome and a Nobel laureate were expected to announce
plans to create a new life form in a laboratory dish in an
experiment that raises ethical and safety questions, according to a published report.
. . Gene scientists Craig Venter and Hamilton Smith
hope to create a single- celled, partially man-made
organism with the minimum number of genes necessary to
sustain life. If the experiment works, the newspaper said,
the microscopic man-made cell would begin feeding and
dividing to create a population of cells unlike any
previously known to exist. The idea is to eventually create
a computer model of every aspect of the biology of a new
organism. Because all living cells are based on the same
chemistry, that could shed light on all of biology.
. . Smith and Venter told the Post the lab-dish cells
would be rendered incapable of infecting humans, strictly
confined and designed to die if they escaped into the environment.
Nov 21, 02: Of all the things that distinguish humans and
other primates --a thumb, the ability to leap and forward-
facing eyes-- it was the ability to grasp that evolved first, U.S. researchers said.
A 56-million-year-old skeleton found in Wyoming shows that
one of the earliest primate ancestors had an opposable big
toe, allowing it to creep to the outermost branches of
trees to hunt nuts and fruit. It also probably kept a sharp
eye out to avoid becoming someone else's meal.
. . Unusually for such an old fossil, the tiny bones of its foot were almost intact. They clearly show a foot that could grasp small limbs and,
unlike other tree-climbing creatures such as squirrels, the
big toe of the foot has a nail instead of a claw. "If you
are actually out on the smallest terminal branches and
grasping, it is probably better to have a nail than claws.
Obviously, we use our hands for all sorts of things that
claws would get in the way of." . "This extends the fossil record of primates back
considerably."
. . The little creature, weighing about 3.5 ounces and
measuring 14 inches from its head to the tip of its long
tail.Unlike living primates, it had eyes that looked
sideways, to help avoid predators, and would have climbed
rather than leaped from branch to branch, Bloch said.
Nov 21, 02: From Chihuahuas to Saint Bernards, all modern
dogs originate from a small number of female wolves living
in East Asia some 15,000 years ago, Swedish scientists
said. By analyzing hair samples from more than 500
different breeds from all over the world, the scientists
discovered that all dogs share the same genetic pool but
that East Asian dogs had a higher genetic variation. "This
makes it probable that dogs originated in East Asia and
spread all over the world."
. . The study looked at dogs' mitochondrial DNA, genes
directly inherited from the mother which present a straight
historical lineage. According to Savolainen it was possible
to see genes from at least five female wolves in today's dogs.
. . Archaeological findings, the oldest being a 12,000-
year-old canine jaw bone found in Israel, had previously
led scientists to believe the domestic dog originated in the Middle East.
The sabertooth cat's social structure may have been less
like the lion's & more like the wolf's, in which monogamous
pairs live together in a pack. No modern cats act this way.
Birds do it too -—stock their homes with sweet-smelling
herbal disinfectants. Evolutionary ecologist Marcel
Lambrechts has found that Corsican Blue Tits scent their
nests with a potpourri of perfumed plants, including
lavender, mint, yarrow, and citronella. And the birds keep bringing fresh herbs, from the onset of egg laying to their offsprings' nestling stage.
Patho-ecologist Karl Reinhard's hypothesis is that
parasites created us the same way we created them. For
example, parasites produced an intense evolutionary
pressure on emerging humans. Those with better brain
capabilities and more memory could better associate
behaviors, avoiding places and using certain medicinal plants, say, to keep from getting sick. So maybe we have worms to thank for our big brains.
Researchers found that children from first-cousin unions
are 1.7 to 2.8% more likely to have a serious birth
defect than are the children of unrelated couples. Although
the elevated risk is significant, "it is much lower than people assumed."
Oct 22, 02: A Californian sea lion called Rio impressed
American researchers by remembering a complicated trick for
10 years without practicing it once --a feat they said
showed sea lions probably have the best memory of all non-human creatures.
Sept 27, 02: Bits of an essay by Seth Shostak: In the
words of Geoffrey Miller, an evolutionary psychologist at
the University of New Mexico, "evolution is driven not just
by survival of the fittest, but reproduction of the sexiest."
. . Miller points out that musty theories claiming we
developed our impressive cerebra from, for example, tool
use, don’t seem to fit the facts. The stone axes chipped by
our one-pound-brained ancestors were about as good as those
made by their three-pound-brained successors. Instead,
Miller suggests that the ramping up of IQ was the result of
100,000 generations of pre-human courtship operating on
fitness signals made possible by brain power.
. . "The brain’s a really good indicator of fitness
because its growth depends on at least half of the genes
that humans have", he says. "A brain, after all, is very
complex, very sensitive to genetic mutations, and costs a lot of energy to run." If you have a good brain, you have good genes. They’re our "Peacock tail".
. . So how can a quality cranium signal its superiority to a mate? It does so with behaviors such as speaking well, or by demonstrating musical ability, a sense
of humor, or creativity. These activities depend upon many
parts of the brain, and consequently are reliable
indicators of mental merit. So males strut their stuff by
crooning, being witty, and speaking well, while the females
use these clues to sort out the best one to take home to mom and dad.
. . And on other worlds around other stars? Miller
laughs: "I think aliens who are obsessed with showing off
their brain power to the opposite sex will be fairly common
out there." . "I think this is one of the key evolutionary
processes that can produce intelligence anywhere in the
universe", he says. "And it’s universal because any
evolutionary system will have some kind of genetic code."
. . So if and when we discover the extraterrestrials,
you shouldn’t be surprised to find that they are slick talkers, good musicians and --unlike their Hollywood ciphers-- able to tell a decent joke.
The evolutionary chain links modern man, chimpanzees, and
a whole host of extinct fossil species to a common ancestor
somewhere about 20 million years ago. A scientific
consensus view puts modern man's origins in Africa some 1.5 million years ago.
Sept 23, 02: Biologists have long held that the genes of
chimps and humans are about 98.5% identical. But Roy
Britten, a biologist at the California Institute of
Technology, said in a study published this week that a new
way of comparing the genes shows that the human and chimp
genetic similarity is only about 95%. He concluded
that at least 3.9% of the DNA bases were different.
Wolf and dog ancestors began to develop about sixty
million years ago. By about twenty million years ago,
canines and felines had branched into two separate families.
There are 17 species of penguins world-wide. Emperor, King, Adelie, African, Chinstrap, Erect-crested, Fiordland, Galapagos, Gentoo, Little (Blue), Magellanic, Macaroni, Rockhopper, Royal, Snares, Yellow-eyed, Humboldt ( the most endangered).
There are only about 6000 Komodo Dragons left, including a
few in zoos. This giant lizard can grow to be 3 meters
long, weigh 300 to 500 pounds, and is the largest lizard in the world.
. . Crocodiles and dinosaurs had a common ancestor
some 250 million years ago (at the *previous great
extinction), but soon diverged into two separate groups.
Aug 28, 02: Chimpanzees lack key parts of a language gene
that is critical for human speech, say researchers.
Last year scientists identified the first gene, called
FOXP2, linked to human language. People with mistakes in
this gene have severe difficulties with speech and grammar.
Human FOXP2 contains two key changes in its DNA compared
with the other animals, the team found.
. . The changes may affect the human ability to make
fine movements of the mouth and larynx, and thus to develop
spoken language. The gene variant that permits language may
have become widespread during the last 200,000 years, Enard estimates. It was around this time that anatomically modern humans emerged. The development of language may have been an important driving force behind human expansion.
. . They think it acts by switching other genes on and off. The two changes aside, the gene is almost identical in humans and the other animals examined.
Aug 27, 02: Researchers found that the tips of the hairs
on the bottom of gecko feet are tiny enough to take
advantage of a weak attraction between individual molecules
--an attraction called the van der Waals forrce.
. . Geckos have millions of microscopic hairs on the
bottoms of their feet that are narrower than human hairs,
and each splits off into 1,000 tips that are so small they
cannot be seen with a conventional microscope and can be
detected only with an electron microscope.
. . The shape of the hairtips is critical. It sticks
its toes to nearly any smooth surface in less than one
eight-thousandth of a second, and unsticks them in half
that time. When that angle reaches 30 degrees, the hair pops off.
. . Earlier studies of gecko feet had reduced the
explanation to either the capillary effect of tiny amounts
of water that create suction or something that worked whether there was any water or not, in this case, the van der Waals attraction between molecules.
Aug 21, 02: A big, black mane is hot, shaggy and attracts
trophy hunters, but it makes a lion irresistibly sexy to
the lionesses, researchers reported. The bigger and darker
the mane, the more mates a lion attracts, and the better
his cubs survive. The higher the testosterone level in the
blood of male lions, the darker the mane.
. . A male with a long, dark mane intimidates other
lions and for good reasons, they found. He has higher
levels of testosterone and wins fights more often. But he
pays for this. He is hotter than lions with lighter manes,
eats less in summer and produces more abnormal sperm. The
mane's evolution is the result of sexual selection.West set
up pairs of model lions with short and long manes and
watched to see which ones wild lions would approach. Males
chose the short-maned dummy nine out of 10 times, she
found, while females approached the darker-maned dummy, 13 out of 14 times.
Aug 14, 02: A study conducted by reasearchers at the
University of California, LA, claimed that consumers
reading a brand name do not treat it like any other word --
instead it activated parts of the brain normally used to process emotions.
Aug 13, 02: A robot has taught itself the principles of
flying --learning in just three hours what evolution took
millions of years to achieve, according to research by
Swedish scientists published. They built a robot with wings
and then gave it random instructions through a computer at
the rate of 20 per second. Each instruction produced a
small movement --the robot's wings could move up and down,
forwards and backwards, and twist in either direction. The
program instructed the robot its aim was to produce maximum
lift, but had no pre-programmed data on the concept of
flapping or how to do it. At first, the robot produced only twitching and jerking movements but gradually it succeeded in getting off the ground.
. . Cheating was one strategy tried and rejected
during the process of artificial evolution --at one point
the robot simply stood on its wing tips and later it
climbed up on some objects that had been accidentally left nearby.
Aug 13, 02: A gene linked to language became widely
established in the human population within the last 200,000 years, perhaps because it helped people communicate better and survive, researchers said.
. . While the FOXP2 gene is not believed to have
caused speech to emerge, it probably allowed humans to
speak much more clearly, said study author Svante Paabo.
The gene became widely established within the last 200,000
years, the researchers concluded after comparing DNA from
humans across the globe. That time is well after the split
between the evolutionary lineages of modern humans and
Neanderthals, Paabo said. The earliest anatomically modern
human first appeared no more than 125,000 years ago.
"People might say if we put this in a chimpanzee, it could
talk. I don't think that is the case, speech is more complex than that", Paabo said.
. . A version of the gene also has been found in
birds, said co-author Wolfgang Enard, also at the Planck
institute. Whether other communicative species, such as
whales, share the gene has not been determined, Paabo said.
Aug 5, 02: Australian scientists have begun work on an
$8.1 million project to track down the gene that produces
the meatiest lamb chops. The sheep genomics project, which
will study what sheep genes do and identify gene markers
for desired characteristics, will also have the potential
to identify parasite-resistant sheep, better disease tests
and controls and deliver meatier lambs.
A new thot in evolutionary biology asserts that the gene
rather than the organism (whether human or worker bee) is
the real entity engaged in the Darwinian competition.
July 31, 02: Skeletal remains of giant kangaroos, wombats
and flesh-eating marsupial lions discovered by accident in
deep sinkholes that pock the Australian outback may be 1.6
million years old, scientists said.
. . The prize among a treasure trove of bones stumbled upon by
adventure seekers is a near perfect skeleton of a marsupial
lion, called Thylacoleo Carnifex, or Leo, thought to have
died out 46,000 years ago --roughly the same time that
humans are thought to have first reached the Australian
continent. The bones of seven other types of extinct
animals, including a pony-sized wombat and possibly the
largest remains of a kangaroo, more than three meters high, were also found.
July 31, 02: Dogs are probably much cleverer than most
people think, according to a new study. Scientists are
convinced that dogs can count and researchers at the
University of California Davis say they try to convey
different messages through the pitch and pace of their
barks. "Animal behaviorists used to think their bark was
simply a way of getting attention. Now a new study suggests that individual dogs have specific barks with a range of meanings", New Scientist magazine said.
Aug 1, 02: A single gene may explain why some boys abused
in childhood --but not all-- grow up to become violent or
aggressive, researchers said. Researchers said 85%
of the boys who had a weakened version of the gene and who
were abused turned to criminal or antisocial behavior. If
the abused boys had one version of the MAOA gene that
caused their brains to produce too little of the enzyme,
they were nine times more likely to become antisocial. The
gene's effects were more difficult to study in girls,
because it is found on the X chromosome. Females have two X
chromosomes, while males have an X and a Y. Thus, in girls,
the version of the gene found in one of their X chromosomes
could cancel out the effects of the other.
July 22, 02: Australian scientists have ended a 40-year
search for a gene which they say could revolutionize rice
cultivation. The gene isolated by the scientists produces
shorter, more productive, varieties of rice. Team leader
Wolfgang Spielmeyer said isolating the gene would speed the
process of creating new rice varieties and help identify
"semi-dwarfing" genes in other cereal crops, such as wheat.
The development of new varieties of rice with shorter
stems, which produced record crop yields throughout Asia in
the 1960s, was called the "green revolution" by scientists.
But the gene responsible had not been isolated until now.
July 24, 02: Scientists have found a new animal species, a
type of centipede which they say may be the world's
smallest, in a most unusual place —Central Park. The nearly
half-inch long centipede is the first new animal species
found in the sprawling New York City park in more than a
century. It's not only a new species, but a new genus as well. Genus is a broader categorization of similar animals that can include 100 or more species.
David Grinspoon: It is always shaky when we generalize
from experiments with a sample size of one. So we have to
be a bit cautious when we fill the cosmos with creatures
based on the time scales of Earth history (it happened so
fast here, therefore it must be easy) and the
resourcefulness of Earth life (they are everywhere where
there is water).
. . This is one history, and one example of life. When
our arguments rest on such shaky grounds, balancing a house
of cards on a one-card foundation, we are in danger of
erecting structures formed more by our desires than the "evidence."
. . Frank Drake: The chemists have found a multitude
of other pathways that produce the chemistry of life.
The challenge seems to be not to find the pathway, but the
one that was the quickest and most productive. The prime
point is that nothing special was required.
. . David Grinspoon: [It is said:] "But no one has
invented another system that works as well as carbon-in-
water." That is true. But to this I would answer, "We did
not invent carbon-in-water!" We discovered it. I don’t
believe that we are clever enough to have thought of life
based on nucleic acids and proteins if we hadn’t had this
example handed to us. This makes me wonder what else the
universe might be using for its refined, evolving
complexity elsewhere, in other conditions that seem hostile to life as we know it.
. . Frank Drake: If we assume that Earths are common,
and that usually there is enough time to evolve an
intelligent species before nature tramples on the biota,
then the optimistic view is that new systems of
intelligent, technology-using creatures appear about once
per year. Based on an extrapolation of our own experience,
let's make a guess that a civilization's technology is
detectable after 10,000 years. In that case, there are at
least 10,000 detectable civilizations out there.
. . On the other hand, taking into account the number
and distribution of stars in space, it implies that the
nearest detectable civilizations are about 1,000 light-
years away, and only one in ten million stars may have a detectable civilization.
July 18, 02: Adding an extra version of a single gene
makes mice grow big brains --brains so large they have to
fold up, much as human brains do, to fit inside the skull,
researchers said. It is not yet clear whether the mice are
smarter --they were all killed soon after birth-- but the
scientists said they were surprised that one gene had such
a strong effect and said they would do further experiments.
. . Mouse brains normally have a smooth surface. Human
brains are all wrinkled and folded. "The thinking power of
the cerebral cortex is determined by surface area. It is
basically a sheet", said Walsh, a neurologist and
geneticist. "If unfolded, it would be 10 times bigger than our head is.
July 18, 02: A shortened version of a gene may make people
more prone to that sweaty-handed, heart-thumping fear that
helped our ancestors survive, a team at the National
Institute of Mental Health reported.
. . Things like temperament are genetic. People who
carry a copy of the short version of the gene react more
than others to scary faces -- and their brains light up
correspondingly. They found that which version you carry of
the gene helps control how you react to frightening stimuli.
July 18, 02: Scientists have found the remains of one of
the weirdest creatures ever discovered --a big flier that
lived during the time of the dinosaurs (110 million years
ago; the middle of the Cretaceous period). They named it
Thalassodromeus sethi. The first word is Greek for "sea
runner". It snapped up fish with a scissors-like beak as
it skimmed over the water, and had a head crowned by a
huge, bony crest. The head was 4-1/2 feet long due to the
size of the crest, a wingspan of nearly 15 feet and a body
length of about 6 feet. Little is known about pterosaurs
because their lightly built bones do not lend themselves to fossilization.
July 4, 02: Catching only big fish can make them evolve
into small fish in just four generations, scientists have
discovered. The surprising result casts doubt on the
fishery practice of letting smaller fish go in the hope
that they will then be able to grow to maturity and sustain fishery productivity.
. . In a new experiment, David Conover of the State
University of New York at Stony Brook shows that when
fishing kills the big fish, evolution selects genes for
slower growth. Historical records confirm old fishermen's
tales that the fish were bigger in the past - the average
sizes of intensely fished species such as cod have dropped significantly.
. . After four generations of removing the
largest fish, the average mass of fish in the 10 per
cent left to spawn dropped to 1.05 grams, compared to 3.17
grams for random selection. After four generations or
removing the smallest fish, the survivors averaged 6.47 grams.
July 3, 02: A fishy four-legged fossil discovered in
Scotland is finally shedding light on the mystery of how
animals first crawled onto land. The new creature, a type
of tetrapod, is the only intact skeleton from this time
period ever unearthed. It resembles an ungainly crocodile
with a whip-like tail and the three-foot long amphibian had
the sensory apparatus of a fish, but limbs and feet adapted
for life on solid ground. The unique fossil is around 345
million years old and has been dubbed Pederpes, meaning rock crawler. "It's by far the earliest leg that looks like it could have been used on land."
July 4, 02: It may not have taken either brains or brawn
for early humans to move out of Africa, researchers said.
Bones of a slightly-built early human with a small head
suggest the large brains that characterize modern humans
did not necessarily evolve before our ancestors began migrating all over the world, the researchers reported in Friday's issue of the journal Science.
. . They describe the skull and jawbone of a small,
lightly-built Homo erectus dug up from a site in Dmanisi,
Georgia. He or she had a small brain, thin brow ridge,
short nose, and large canine teeth. It was found with
specimens that had bigger skulls, but all were about 1.75 million years old.
June 24, 02: Argentine paleontologists have found bird-
like footprints 55 million years older than the oldest
known bird fossils. The team discovered dozens of three-
toed footprints in rocks older than 212 million years in
northwest Argentina. Averaging about 3.5 centimeters wide
and similar in length, they look very much like bird
footprints made in small shallow ponds along a river.
However, the rocks are some 55 million years older than the
most ancient known bird skeleton, Archaeopteryx. The big question is what made them.
. . Paleontologists believe birds evolved from small
two-legged predatory dinosaurs called theropods between
five and ten million years before Archaeopteryx lived, 155
million years ago. Archaeopteryx had flight feathers, but
its skeleton looked like a small theropod dinosaur.
Researchers have since developed tests that help them tell
the birds from the dinosaurs. The Argentine prints pass
most of them. Their structure, the environment where they
formed, and their high concentration all favor an avian
origin. The Argentine footprints have a key feature not
known in any theropod: a reversed hallux, the backward-facing toe of modern birds.
. . The footprints might revive interest in a
controversial fossil of the same age. They are the right
size to match "Protoavis", says Sankar Chatterjee of Texas
Tech University, who for a decade has had little success convincing other paleontologists that his discovery in the late 1980s was an ancestral bird.
Apr 24, 02: Researchers announced the discovery of the
earliest known ancestor of the group of mammals that give
birth to live young. The finding is based on a well-
preserved fossil of a tiny, hairy 125-million-year-old
shrewlike species that scurried about in bushes and the low branches of trees.
Apr 1, 02: Once deciphered, RNA genetic clues reveal that,
of all animals, sponges are the most genetically distinct.
Jellyfish and anemones share slightly more genetic
similarities with each other and with other animals.
. . This finding led Sogin to conclude that sponges
occupy the oldest and lowest branch on the animal family
tree. Because the higher branches have introduced
additional innovations that account for animals' rich
diversity, he says, the common ancestor of all animals
probably resembled modern sponges much more closely than anything else alive today.
. . "The special evolutionary relationship between
animals and fungi was a big surprise", Sogin says. "In many
regards, fungi are similar to primitive plants." Yet the fungus, he has concluded, shares "a unique, common evolutionary history with the animal."
. . Some details of early animal evolution still
remain to be worked out. In particular, Sogin would like to
know whether certain types of fungi are more closely
related to animals than other types. If they are, it would
mean that the entire animal family is just a branch on the evolutionary tree of the fungi. In a sense, people -—and all animals—- would be highly evolved fungi.
March 21, 02: A pint-sized dinosaur dug out of 140 million-
year-old deposits in China is an ancestor of a triceratops,
the frilled dinosaur. It was 1/3 meter high & 3/4 meter
long, about the size of a small dog, the smallest and
oldest member of the neoceratops clan to be found. The
little creature had horns under its eyes and a small frill
similar to those seen on the giant triceratops that evolved later.
March 5, 02: Chinese and American scientists have
unearthed a fossil of a small, feathered, flightless
dinosaur in northern China which they say is definitive
proof that feathers originated before birds or flight.
. . Paleontologists have found evidence of fluff or
fuzz on other ancient creatures, but this is the first
evidence of feathers in a Dromaeosaur, thought to be one of
the closest relatives of birds. The new feathers are
structurally identical to those of modern birds.
Dromaeosaurs belong to a group of dinosaurs called
theropods which share about 100 anatomical features,
including a wishbone, swiveling wrists and three forward-pointing toes, with birds.
Feb 27, 02: T. rex was a slowpoke. The most feared and
revered of the dinosaurs did not have the leg strength to
run very fast, if at all, according to a computer model
developed by two experts in the mechanical movements of living creatures.
. . The Jurassic Park chase went 70 kph. According to
Hutchinson and Garcia's model, that's impossible. 86% of T. rex's body mass would have to be leg
muscle for the behemoth dinosaur to run that fast.
"Supportive leg muscle is usually only 5 to 20% of
an animal's mass." The computer model estimates a top speed between 16 and 40 kph.
. . A 1995 study concluded that the strength of T.
rex's thigh bone relative to its body mass was not strong
enough to support fast running. The paper also shows that
T. rex was at serious risk of injury if it fell.
Feb 13, 02: A 130 million-year-old newly discovered fossil
of a small meat-eating dinosaur found in China is further
proof of the evolutionary link between dinosaurs and birds, scientists say.
"This animal is not a direct ancestor to birds but it is a
very close cousin. It is from a group called troodontids which
is closely related to birds", Peter Makovicky of the Field Museum in Chicago said.
. . The new dinosaur, called Sinovenator changii, was probably
feathered and is almost the same age as the oldest known bird --Archaeopteryx.
. . Sinovenator was a two-legged predator like the mighty
Tyrannosaurus rex but it was the size of a large chicken with a
skeleton less than three feet (one meter) long. It had a bird-like shoulder joint, a wishbone and a pelvic bone that points backward, similar to modern birds.
Jan 1, 02: Scientists agree that whales are actually
highly specialized ungulates, or hoofed mammals.
. . In recent years, molecular biologists have put
forth a different hypothesis -—based on DNA from living
animals—- asserting that the ancestors of whales were
instead artiodactyls -—a group whose extant members include
hippopotamuses, pigs, camels and ruminants. Furthermore,
several molecular studies have concluded that whales share
a common artiodactyl ancestor with hippos and are thus more closely related to these animals than to any other living artiodactyl or to a mesonychian.
Ant genetics dictate that females are more closely related
to their sisters than their brothers. That's because
females develop from fertilized eggs and possess two copies
of every chromosome -- one apiece from the mother and
father --while males arise only from unfertilized
eggs and carry just one copy of every chromosome.
Many have considered "biocontrol" agents to be environmentally friendly. But now there is mounting concern that alien species can do more harm than the very pest or
weed they are intended to eliminated. New research definitely showed the biocontrol agents had turned to attacking native species in a natural ecosystem.
Sept 19; 01: Fossils recently unearthed in Pakistan show
that whales evolved from land animals related to sheep and
pigs, and that hippos could be their closest living kin,
scientists said. The newly discovered fossils show the
first whales were fully terrestrial, and were even efficient runners!
. . Fossil evidence of the whale's 10-million-year
transition from land to water has been sketchy.
Paleontologists earlier have discovered 50-million-year-old
fossils of early whales that lived on land, and ankle and
skull bones from primitive aquatic whales that fill in the gaps.
Sept 6, 01: Scientists announced the discovery of the
oldest known hominid fossils yet found in southern Africa,
dating back 3.5 million years. Limb-bones and cranial
remains of the genus Australopithecus were uncovered at the
world-renowned Sterkfontein Caves, north of Johannesburg.
. . Older hominid fossils have been uncovered in East Africa,
with finds in Kenya and Ethiopia dating back to 5.7 million
years and more, boosting Africa's claim to being the "cradle of humankind."
. . From the molecular evidence such as DNA, it had been held for many years that humans and apes, chimpanzees in particular,
parted company five to seven million years ago", said Tobias. "But new evidence in Ethiopia and Kenya is forcing us to push that parting of the ways back further in time to perhaps as far back as seven to nine million years ago."
Aug 9, 01: The first land plants and fungi emerged from
the seas and colonized Earth's rocky, barren landscape
hundreds of millions of years earlier than previously
thought. Researchers at Pennsylvania State University, in a
study appearing in the journal Science, said land plants in
the form of mosses appeared about 700 million years ago and
land fungi in the form of lichens about 1.3 billion years
ago. Until now, scientists had believed plants and fungi
first appeared on dry land around 480 million years ago,
based on their oldest-known fossils.
. . The oldest known land animal was a tick-like
creature from 460 million years ago. Aquatic fungi evolved
into a terrestrial form about 1.3 billion years ago, the study found.
. . Somewhere between a billion and 700 million years
ago, a lineage of green algae evolved into primitive land
plants like a green moss or the small, brownish liverwort.
Aug 1, 01: Computer graphics of Neandertals based on
ancient fossils show they were very different from early
humans and did not mix with them, Swiss scientists said.
. . "This is a strong argument for early separation on the species level, which means they had isolated populations. There might have been some accidental inbreeding but certainly not a big exchange of genes."
. . "We think that together with the genetic data ...
it is quite reasonable to think that these are really two different species [that] separated at least half a million years ago", said Zollikofer.
. . Along with carbon dioxide, water and light,
plants need nitrates to survive. The ancient, higher levels
of atmospheric nitrogen provided more than enough nitrates
for the plants because lightning, it was theorized by the
Ames/UNAM researchers, catalyzed an atmospheric carbon
dioxide and nitrogen reaction that made nitrate foods for Archaean-era life forms.
. . This changed when carbon dioxide levels dropped
dramatically. Ancient soil samples show this drop lasted
over 100 million years during the Archaean Era, drying up
the nitrate supply along the way. This had to have forced
the plants to find a way to make nitrogen on their own.
. . This advance in plant evolution would have
allowed for plants to colonize more environments on Earth,
he said, and this proliferation eventually raised oxygen
levels in the air and made an environment suitable for animals later.
July, 01: . . The fossils of a new subspecies of an
early relative of humans were found 140 miles northeast of
Addis Ababa in Ethiopia. The jaw, collar, feet and arm
bones are from about five individuals of the new subspecies
of Ardipithecus. They are about 5.4 to 5.7 million years
old, about a million years older the previous oldest known
hominid, according to the researchers. That's about 2.5
million years older than Lucy. It is the earliest hominid,
pushing back the record by more than a million years.
. . Scientists suspect the evolutionary line that led to
humans diverged from the line leading to our closest ape
relatives about five to six million years ago. "We now
know that the split with chimpanzees did not happen five
million years ago because we have hominids that are 5.5 or 5.6 million years old."
. . A toe bone indicates the Ardipithecus subspecies
walked on two feet when on the ground. Evidence suggests
the earliest hominids lived in wooded, wet environments and
did not venture into more wide-open spaces until about 4.4 million years ago.
May 10, 01: In a new twist to the puzzle of how life
developed from only left-handed amino acids, researchers
have found that the common mineral calcite can segregate
the molecules into their left-handed and right-handed varieties.
All life is made up of cells built and operated by
proteins, which in turn are made from 20 building blocks
called amino acids. No one knows why only 20 are used, but
that is an unbroken rule in all of biology throughout the
history of life on Earth, from the smallest bacteria to the
prettiest flower to the largest WWF wrestler.
. . By rewriting the genetic instructions inside
bacteria, two separate research groups tricked the one-
celled microscopic critters into incorporating a hitherto
unused amino acid into the process of building proteins.
. . Schimmel said the bacteria survive and reproduce,
even though their proteins are chugging along with an alien amino acid.
. . If life forms are ever found on Mars or
elsewhere, scientists would now be better equipped to
determine whether a true alien has been found or whether
we've just met back up with ancient ancestors that somehow
traveled from one celestial body to another.
May 9, 01: A mass extinction at the boundary between the
Triassic and Jurassic periods during the Mesozoic era was a
sudden event, not the prolonged die-off that experts previously had thought.
. . The dinosaurs were wiped out by an asteroid that
smacked the Earth 65 million years ago, but they survived
another cataclysmic event --perhaps another asteroid impact-- that snuffed out 80% of all species about 200 million years ago, scientists said.
. . In the extinction 199.6 million years ago, the
mammal-like reptiles --whose earlier forms gave rise to the
first true mammals-- perished in the calamity.
. . "One of the great mysteries has been ... why
would these creatures, which are seemingly better adapted
for eating a variety of plant sources, die out and the
dinosaurs not? And the answer is: Mass extinction doesn't
give a hoot about your adaptations for everyday life.
There's a lottery involved, for whatever reason", Ward
said. He has found evidence of little carbon molecules
called buckminsterfullerenes --buckyballs-- that hint at a
space rock as the culprit. He said a massive crater in
Quebec called the Manicouagan structure, which measures 100
km (60 miles) wide, could be the impact site. The crater
has been dated to 214 million years ago, but Ward said the date may be too old.
. . Scientists know very little about the mass
extinctions that took place 350 million and 420 million years ago, Ward said.
. . At present, we know that there are about 1,000
asteroids roughly larger than 1 km in diameter whose orbits cross Earth's. These are large enough to inflict serious global consequences in a collision.
Homo sapiens is thought to have appeared about 50,000
years ago. There is an estimate of a total 106 billion
humans born. The 6.1 billion living at present therefore
represent 5.7% of all who have lived.
A human egg is stuffed with over 100,000 mitochondria
while a sperm brings none into the egg.
May 11, 01: Genetic research unveiled provides compelling
support for the theory that anatomically modern humans rose
out of Africa in the past 100,000 years and swept aside
populations of archaic humans, with *no inter-breeding.
. . A team of Chinese and American geneticists
obtained blood samples from more than 12,000 men from
across east Asia and examined characteristic DNA sequences
called markers on the Y chromosome (the male chromosome).
. . The Y chromosome is considered one of the most
powerful molecular tools for tracing human evolutionary
history because it remains unchanged over eons when passed from father to son.
. . The researchers found that every one of the men
could trace his ancestry to forefathers who lived in Africa
over the past 35,000 to 89,000 years. They also found
absolutely no genetic evidence that the modern people (Homo
sapiens) mated with archaic humans (Homo erectus) that
already lived in Asia, having migrated from Africa about 1 million years ago.
. . There is absolutely no genetic evidence that the
modern people (Homo sapiens) mated with archaic humans (Homo erectus) that already lived in Asia, having migrated from Africa about 1 million years ago.
. . When scientists sequenced the DNA from the
mitochondria (tiny structures within a cell but outside the
nucleus that contain genes) of a Neanderthal four years
ago, they found it was vastly different from that seen in people today.
. . "The genetic evidence implies a recent common
origin of our species. The Y chromosome really makes that
argument bullet proof,'' Stanford University molecular
biologist Peter Underhill, a study co-author, said in an
interview. "All these people trace their roots back to a
common ancestor who lived in Africa maybe 100,000 years ago", Underhill said.
May 18, 01: The elephant's trunk has multiple uses--nose,
hose, and tentacle. Now, Australian embryologists believe
they have evidence that could point to the trunk's original
purpose. The elephant, they believe, was an aquatic animal that moved back to the
land. If that's true, then the elephant's trunk may have evolved as a snorkel.
May 18, 01: Studying the chemicals that remained in the
bones of the earliest modern humans, scientists discovered
that their diet, which included fish and fowl as well as
large mammals, may have given Homo Sapien the edge over the
Neandertals, who favored an all-big-mammal menu.
. . The key to the modern humans' survival was a more
diverse diet, which gave them more choices in lean periods.
Vegetables and fruits played little role in the diets of
Neandertals and early modern humans, he said. "They [ate] some (vegetables and fruits) but it was not enough to show up in their bone chemistry", Richards said.
May 20, 01: Many who believed their ancestry to be
completely British are actually far more diverse. In a DNA
study of more than 10,000 people, 1% of "white" Britons is
descended from an African or Asian. The study's author,
Bryan Sykes, professor of human genetics at Oxford University, believes the DNA originates in Africans brought to Britain as soldiers and slaves by the Romans.
May 9, 01 - Humans could be reaching new evolutionary
heights because tall men have more children and height is
estimated to be about 90% genetic, a science magazine said.
. . Mazur and Ulrich Mueller, of the University of Marburg in
Germany, studied men who graduated from the U.S. military academy
at West Point in 1950. German and American researchers
have discovered that tall men are more likely to divorce
and remarry and when they do, they usually choose a younger second wife.
. . "Tallness is pretty much universally attractive.
The more attractive a man is, the more chance he gets to
destroy his first marriage", Allan Mazur, of Syracuse
University in New York, told New Scientist magazine.
. .Regardless of rank, height was the significant
factor in the number of marriages, divorces and children.
Taller men had more of each than their shorter colleagues.
Eleven-year-old Japanese boys are five inches taller today
than their counterparts 50 years ago. In Britain, the
average height of adolescent boys has shot up nine inches since the 1830s.
May, 01: Chomsky's theory has been bolstered by a study of
deaf children who have never been exposed to conventional
language, either spoken or signed--yet who develop their
own complex language of gestures, complete with unique
grammatical rules. These rules are amazingly consistent
across cultures: virtually identical gesture patterns
developed spontaneously among both Chinese and American children.
Feb 6, 01, The United Nations News: A rare breed of wild,
salt water-drinking camels found in China and Mongolia are
now thought to be a different species from their domesticated cousins.
May, 01: Researchers concluded that there would have been
20 "globally devastating" impacts during the past 5 million
years, with effects strong enough to have had "a
catastrophic and detrimental effect" on human evolution.
Five million years ago is roughly the time when hominids
diverged from other apes, though some recent controversial
evidence puts the split as far back as 6 million years ago.
. . There were probably only five or 10 with enough
energy to create global environmental effects.
. . There has been debate for over 100 years on
whether evolution is gradual or punctuated. Peiser said his
study supports punctuated equilibria, and helps explain why
"almost all hominids, i.e. the 14 known species of human
ancestors, have become extinct during the last 5 million years."
. . Cold periods are suspected of forcing migrations
that created small, isolated groups that could have evolved
significantly but then died out. One such period may have
occurred as recently as 71,000 years ago. But firm links
between climate and serious evolutionary changes elude researchers.
Our primate ancestors, scampering about the rain forests of China, were incredibly small-no longer than a human thumb. The creature weighed just one third of an ounce and
probably dined on fruit, nectar, and insects. "This is by
far the smallest primate that's ever been found, alive or extinct."
William Whitman of the University of Georgia recently calculated there are 1X1030 bacteria on the Earth! --that's 1 followed by 30 zeroes.
May, 01: The oldest whale fossil yet known: a 53.5-million-year-old creature called Himalayacetus.
More than 100 million years before birds made their appearance, an intrepid, lizardlike animal called Coelurosauravus developed its own way to get off the ground. New studies show that Coelurosauravus used a unique gliding strategy unlike that of any living animal --and it might have been the best glider the world has ever known.
. . The well-preserved skeleton showed that Coeluorsauravus had at least 22 wing bones on each side, but only 13 vertebrae. The wing bones were clearly not
extensions of the ribs. More surprising, Sues realized that
the bones were not attached to any part of the skeleton.
. . "These were bones that had evolved specifically
for the purpose of supporting a wing", Sues concludes. "Most animals modify their arms into wings, but this animal actually has four legs and then wings." Coelurosauravus's
rodlike wing bones were hollow, like those of modern birds,
and supported a membrane of skin. The rods were arranged so
that the creature could fold its wings back against the
body and then unfold them like a Japanese fan. When spread, the wings were slightly concave, providing lift; a long, slender tail might have aided steering and balance.
. . They built a scale model of Coelurosauravus and
tested it in a wind tunnel; the results affirm the little
reptile's aerodynamic prowess. "It could climb up a tree
and just hop off, and glide for a hundred, perhaps hundreds of feet."
Mar 21, 01: Scientists have discovered a 3.5 million-year-
old skull in Kenya Kenyanthropus platyops, or "flat-faced
man of Kenya." Meave Leakey said the chances are 50-50 that
this species --and not Lucy's species, Australopithecus
Afarensis-- was an early direct ancestor of humans.
3-00: A new method of calculating oxygen in the Earth's
atmosphere suggests that an increase more than 300 million
years ago was caused by the rise and spread of trees and
other vascular land plants (plants that transmit sap through a system of vessels).
The higher concentrations of oxygen appear to have
lasted for 100 million years and were significantly higher
than the Earth's current oxygen content of 21%. This high oxygen may have been an important factor in affecting the evolution of giant insects.
Oct 9th, '00: Teeth and bits of jaw from a tiny, squirrel-sized animal
that lived 40 million years ago in what is now Myanmar (Burma) suggest primates originated in Asia, not Africa as was believed, researchers said.
3-16-99: Scientists at Harvard switched 3 genes in a
chicken embyro and made a wing into a leg! Only one gene-
switch could "turn on" teeth! Not so difficult to engineer
a new dino"saur", is it? (They were bird relatives, not
reptile, tho further back, there was a common ancestor.)
2-1-99: "Anybody who objects to cloning on principle
has to answer to all the identical twins in the world who
might be insulted by the thought that there is something offensive about their very existence. Clones are simply identical twins." Dr Richard Dawkins.
Evidence: Neandertals survived in Europe as recently as 36k years ago. Coexisted with Cro-Magnon (us). Looked like wrestlers beside basketball players, relatively. Shortness is a good adaption to a cold climate. Tall is easy to cool, yet Bantu
live by Masai. The Cro-Magnons originally gracile build
became less so, reaching modern average about 20k ago.
. . Anatomically-modern humans came about 92k yrs ago. / Stone tools: Pakistan, 2mil ago. /Charred bones (use of fire): 1-1.5 million ago.
The Miller-Urey experiment, in the 60s (?), bottled up
methane and ammonia, etc, zapped the mixture with "lightning, and found amino acids --the precursor of life. This showed the possibilities, but lately...
. . "Shortly after the experiment was published,
however, geologists came up with new findings on Earth's
volcanic emissions --and threw the old reasoning for a loop. "What comes out of volcanoes is not [that]" Kasting said, "but about 80% water vapor, 15 to 20% carbon dioxide, and traces of carbon monoxide and molecular hydrogen."
. . James C. G. Walker, one of Kasting's graduate advisers at the University of Michigan during the 1970s, took these emissions data and balanced them against the
rate at which hydrogen would be expected to escape from a
planet with Earth's gravity. ("He did all this stuff on the
back of an envelope", Kasting said.) Walker came up with a different picture of Earth's early atmosphere: an oxygen-rich mix of carbon dioxide, nitrogen, and water vapor.
. . The catch is that oxygen is poison to pre-biotic
synthesis. Do a Miller-Urey experiment in an oxygen-rich atmosphere, Kasting said, and "you don't form things like amino acids. There are too many oxygen atoms in there." So, "enthusiasm for the warm little pond theory has waned."
. . Under some circumstances, RNA can replicate on
its own. Not only that, but it can store genetic
information. RNA, in other words, can do it all. "Early
life is now believed to have passed through a stage in which only RNA was present."
. . RNA: ribose, a sugar; phosphate, a salt; and the four bases -- adenine, cytosine, guanine, and uracil (the last is where the thymine is, in DNA).
. . Eukaryotes, she explained, are distinguished from
other microbes by their complexity: the internal membranes,
the machine-like organelles, and, most important, a core nucleus. "It's this structure that allows for differentiated cells, and lets multicellar organisms arise."
. . Prokaryotes: bacteria and archaea-bacteria. A
more humble class of organisms, these. No impressive
innards: no mitochondria, no nuclei. No internal membranes enforcing structure.
. . The "minimal genome" for an ancestor that could
have given rise to all of life would have to include at
least 256 genes. (Yeast, a fungus, has 5,000 genes; humans
have roughly 30,000--not the 100k we thought till recently.)
. . Birds, which are warm-blooded, are actually
closer to lizards than they are to mammals."
. . Over the long haul, a given gene evolves at a
constant rate. If you know that rate, and you know that the
gene is present in a pair of organisms, counting the number
of changes that have occurred in each will yield the length
of time since the two diverged from a common ancestor.
. . "We've come up with divergence times for early
splits in vertebrates that match up well: amphibians from
reptiles and mammals at 360 million years ago; trout and
salmon from other fishes, 450 million. . . . For the split
between humans and chimps we got 5.5 million, which is
close to the time assumed by most anthropologists."
. . Evolution's Big Bang. The fossil record is rich
with specimens from the dawn of the Cambrian period, 540
million years ago. But molecular data collected in labs
around the world over the last 20 years, Hedges said, tell
a different story. According to the DNA, "Animals diverged
one billion years ago, not 540 million.
. . "Maybe they were soft-bodied, and therefore
rapidly decaying. Maybe there was an increase in size right at that boundary.
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