Apos
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Asus said:I just thought I'd bring something else up. In order for an animal to evolve, it's features must be made and grow over this long period of time. Yet if an animal only grew part of this transformation because of it's new environment, wouldn't natural selection remove this animal with these weaker and incomplete parts? Something to think about...
Not really, because that's not how evolution works. Animals don't "grow" new features in any sort of deliberate, forward looking manner that envisions a final product but takes many steps to get there. Indeed, it's wrong to even think of evolution happening to an animal: evolution happens to _populations_, not single lines of descent. An example is a population of finches among which are a wide variation of beak lengths (variation). These beak lengths may have different survival advantages, which skew the next generation in a particular direction (selection). It doesn't happen in the way most people seem to think: that there is some finch that magically reproduces a finch with a longer beak because that's what's best.
Each minor change in a population has an advantage, and it adds up over time to larger changes: that's all. In some cases, features that might have served one purpose in one environment can play different roles in another, or side effects of one process can ultimately prove even more advantageous than the original feature.