Theories about the origin of life on Earth
1. __________________________ - life was carried by asteroids or meteors
2. __________________________ - a supreme being created the Earth
3. __________________________ - originated from nonliving matter
The Earth is ________________ years old. The oceans are ___________ years old. Life arose from nonliving matter ________________ years ago. The earliest life on earth was ______________. Eukaryotes arose ____________ years ago. Major animal groups evolved _____________________ years ago. There have been ___ mass extinctions on this planet.
Theory of Evolution
1. ________________ exists within the genes of every species.
2. In a particular environment, some individuals of a species are better suited for survival & so leave more offspring. This is called ____________ _______________.
3. Over time, change within species leads to the replacement of old species by new species as less successful species become ____________.
4. There is clear evidence from _____________ & many other sources that the species now on Earth have _____________ from ancestral forms that are now extinct.
_____________________________ was the first scientist to develop the 1st major idea of evolution in 1809. he believed in ___________________ ___ ________________ __________________ which states that by selective use or disuse of organs, organisms acquired or lost certain traits during their lifetimes. These traits could then be passed on to their offspring & this process leads to change in a species.
The economist _________________________ also influenced the ideas of evolution. By observing population growth, he reasoned that if the human population continued to grow unchecked, sooner or later there would be insufficient living space & food for everyone.
____________ developed the major theory of evolution. He took a voyage on the ______________ through the _______________________ Islands. He saw certain patterns & saw that species changed over time & gave rise to new species. He also observed finches & observed adaptations of these birds & other animals. Darwin wrote On the Origin of Species by Means of Natural Selection. There are 5 main points associated with natural selection.
1. Individuals of any population vary from 1 another – even siblings differ.
2. These variations can be inherited.
3. Populations produce more offspring than the environment can support.
4. Those individuals with favorable variations are likely to leave more offspring.
5. The passing on of favorable variations leads to the population evolving gradually.
A ________________ is the preserved or mineralized remains or traces of an organism that lived long ago.
Darwin began explaining evolution by arguing that ____________ _______________ occurs in all organisms. By observing farmers, Darwin observed ____________ ______________ that allowed humans to select variations that they found useful. This shapes a variety of traits.
Darwin called the ability of an individual to survive & reproduce in its specific environment _____________. He proposed that this is the result of adaptations. Individuals that are better suited to their environment survive & reproduce most successfully. This is called ____________ ___ ____ ______________. Darwin also called this ______________ _________________. This leads to changes in the inherited characteristics of a population. These changes increase a species’ fitness in its environment.
Darwin also proposed ___________ ____ ________________ that states that each living species has descended, with changes, from other species over time. This leads to the principle of _________ _________ that states that all species, living & extinct, were derived from common ancestors.
_______________________ structures are structures that share a common ancestry. These have different mature forms but develop from the same embryonic tissues. Examples would be the bones of the arm of penguins, gators, bats, & humans. ____________________ structures are remnants of the evolutionary past – they are no longer used. These are usually reduced in size. Examples in humans are the tailbone, pointed canines, muscles to move the ears, the appendix, & nicitating membranes on the eye. The evolutionary history of organisms is also evident in their __________________ development. Closely related species show more similarities in their ___________________ sequences.