Staying Alive
Over time, those plants or animals which are best suited to the conditions
in a habitat tend to be those which survive. Living things can hedge their bets by
- reproducing themselves. This can help increase the odds of survival, particularly if new individuals expand into new locations.
Favourable genetic traits can be passed along to the next generation.
Also, some animal species teach "life skills" to their young, another
form of inheritance from the previous generation.
- genetic variation. Nature worries more about "getting the job done" than an elegant solution
or producing an exact replica each time. Variations in the end-product can provide an opportunity
to expand into a new niche or better compete in the existing one. Variety also helps ensure that
a species doesn't put all its eggs in one basket.
- protecting a territory against competitors. This encourages expansion and also helps
prevent overconsumption of finite resources because an area is over-populated.
It is harder to displace a living thing already established in its niche than
to take advantage of a new niche.
It doesn't always pay to over-specialize. When some plant species were bred for higher crop yields,
characteristics such as resistance to disease were lost which still exist
in the wild version of the plant.
Some organisms coevolve either with other organisms. For example,
- a natural interdependency may form between a plant and the creatures that pollinate it.
- By selective browsing, moose populations can affect the plant
populations in their habitat. This, in turn, can affect the suitability of that habitat
for other animals.
- Sea otters help control the sea urchins that otherwise would kill off the kelp forests
that these sea mammals inhabit.
There are also certain trade-offs in design.
Some animals such as birds may use more than one habitat by migrating to a different
habitat when food is abundant there.
Related Links
Back to Habitats
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