Tuesday, December 13, 2005
What is evolution?
Evolution is a change of gene frequency in a population. So you have all seen it happen in your lifetimes! For example, take the population of cats in your neighborhood. When you moved in, let's say there were three grey Siamese cats. But now those Siamese are no longer around (one died of old age, one wandered off, and one got hit by the garbage truck). There are still cats, though: two tabbies, a huge coon cat that belongs to the codger down the street, a mean old orange cat, and a feral black cat that just had five kittens. So the population of "cats in your neighborhood" is now different; and by the way I have described them, their gene frequencies are different than when you moved in. Voila!! You have witnessed evolution in operation. So what do evolutionary scientists study? Just the things that happened in your neighborhood: births, deaths, migrations, and the selective pressures that affect any of those three processes.
# posted by Atrox @ 7:54 AM 
