Evilution

A study released this week states that since chimpanzees and humans diverged genetically 6 million years ago, chimpanzees have evolved more than humans. Scientists (those evil, godless heretics) found a greater ratio of positive mutations in DNA to silent (non-expressed) or negative mutations than in humans. The article I linked does point out a great number of mitigating factors that may nullify the results, such as there being a much larger population of chimps than humans over the time period since the split. However, the conclusion reached brings up an interesting point, that humans have removed themselves from the evolutionary chain.

To put it simply, humans have stopped evolving at a rate consistent with the rest of the natural world. First, what causes evolution? As I understand it, evolution is the result of many factors, but primarily it is the selection of beneficial genetic mutations over time resulting in genetic and physical changes in a population. Those changes that are advantageous are kept in the population via the carrier not dying. Usually these changes go unnoticed (silent) or are quickly eliminated by the death of the new mutation. However, as the environment changes, a genotype that once worked may not be as efficient as before, and a new genotype arises that is more efficient and outcompetes the older type, resulting in a change in population or even extinction. The key word here is "environment". Environment does impact genetic change, but almost always indirectly (weeding out the ineffective genotype/rewarding the more effective type). So with that in mind, I would postulate that humans have removed themselves from the environment that they have ceased to evolve. If the environment remains static, there is no need for adaptation, and diversity in the population goes to zilch. This is of course bad, because when there is a shift in environment (and because of how we live that shift will most likely be swift and dramatic, as opposed to the long and drawn-out time frame needed for evolutionary change), then humans will be left in the dust, as it were.

Now I'm absolutely talking theory here, with very little evidence to support my claim. It's mostly an exercise in thought - I was originally going to write about how bad California drivers are (again) but heard this story on the radio as I was coming home. Or better yet, what if humans began adapting to our current sheltered environment of plenty? Would we see a decrease in brain size or cerebral folding as we rely more and more on technology, a body more suited to metabolizing fat and artificial chemicals as we ruin the natural food supply, less muscle mass as we continue to use and abuse transportation systems? Whatever the answer, it's still an interesting and frightening idea with a whole lot of pride wrapped up in it - how come we, as a species, are exempt from the natural order? We have been living outside of the natural order for thousands of years, ever since we began creating unnecessary surpluses and warring against the environment rather than living within it. Ah, so. Time for homework.