Friday, October 26, 2007

Future Human Evolution

This is one of the dumbest things I've heard of, for many reasons.

While there does seem to be some evidence of the division into "gracile" and "robust" forms in primates, Oliver Curry mistakenly says that chimpanzees split into robust chimps and gracile bonobos. This is not true. The common ancestor of humans, chimps and bonobos split into the descendants of chimps and a second group that itself split into the descendants of the bonobos and the descendants of the humans. We can see this in the fact that we are more closely related to bonobos and that we share some anatomical and behavioral features with bonobos, though many of our behaviors more closely resemble chimps, while bonobos physically resemble chimps more. So the evolutionary picture is more complex than Curry suggests.

The next bizarre statement, from an evolutionary point of view, is that "human evolution will reach its peak in about the year 3000." I don't know what this could possibly mean. Evolution does not have "peaks" in the sense that a species is as good as it gets. Species are always adapting to their environments. Humans are a strong generalist, and we are thus highly adaptive to practically every terrestrial environment. This leads into the nonsense about genetic regression. There is no such thing as genetic regression -- there is only more or less adaptive species to their environment.

This then leads me to the issue of evolution itself. When a species is as mobile as our own -- especially in the modern world -- natural selection as adaptation to the environment no longer occurs. What we have now in control is population dynamics, where a genetic change spreads rapidly and evenly throughout a population after a few generations. Now, Curry mentions sexual selection. But I see no evidence for differences in sexual selection. All the studies that have been done my evolutionary psychologists show that people universally find the same general proportions physically attractive. Globalization is, again, even eliminating many of the cultural differences that may (as unlikely as that is, since those differences were never actually substantial) have contributed to sexual selection. The elements contributing to intelligence, as I noted in a previous post, are so numerous as to make it difficult to determine what combinations are best.

This is not to say that over the time span he mentions -- 100,000 years -- that human evolution won't occur. Sure by then we will have colonized the moon and Mars, perhaps even the stars. And one would expect those isolated populations to evolve. But to keep things more down-to-earth, Curry fails to mention another type of evolution. It is a more important kind, and it is the kind that gave rise to human intelligence itself. And that is the evolution of more complexity. It is possible that certain people might evolve to have more complex minds -- perhaps as much more complex than humans as humans are over chimps and bonobos. It is unlikely they would appear to be physically any different, as the difference would be in the minds of the people who emerged into the more complex forms ot thinking. This kind of evolution seems more likely, and it seems more immediately likely. And if Claire Graves, Don Beck, and Christopher Cowan are right, it may have already happened in a small group of people. That is a much more interesting kind of evolution in my book.

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