October 19, 2005


Evolutionary Genetics: Are Humans Still Evolving?: The goal of much of modern medicine and culture is effectively to stop evolution. Is that happening? (Michael Balter, 8 July 2005, Science)

The news made headlines around the world: Blonds were going extinct. According to CNN and other media, a World Health Organization (WHO) study concluded that the gene for blond hair, which was described as recessive to dominant genes for dark hair, would disappear in 200 years. The BBC announced that the last natural blond would be born in Finland and suggested that those who dyed their hair might be to blame, because "bottle blonds" were apparently more attractive to the opposite sex than natural blonds were and thus had more children.

Fortunately for blonds, the whole story turned out to be a hoax--"a pigment of the imagination," as the Times of India later put it. WHO announced that it had never conducted such a study, and hair color is probably determined by several genes that do not act in a simple dominant-recessive relationship. The story, which may have originally sprung from a German women's magazine, apparently simply leaped from one media outlet to another.

Although the story was untrue, the ease with which it spread reflects popular fascination with the evolutionary future of our species, as well as the media's appetite for evolutionary pop science. Today, Oxford University geneticist Bryan Sykes is receiving voluminous coverage for his book, Adam's Curse, which predicts that continuing degeneration of genes on the Y chromosome will leave men sterile or even extinct in 125,000 years. Many biologists say that the question they most often receive from students and the public is "Are humans still evolving?"

To many researchers, the answer is obvious: Human biology, like that of all other living organisms on Earth, is the result of natural selection and other evolutionary mechanisms. Some say the question itself betrays a misunderstanding of how evolution works. "The very notion that ... we might not be evolving derives from a belief that all other life forms were merely stages on the way to the appearance of humans as the intended end point," says primatologist Mary Pavelka of the University of Calgary in Canada.

But other scientists point out that in developed countries, culture, technology, and especially medical advances have changed the evolutionary rules, from survival of the fittest to the survival of nearly everyone. The result, they say, is a "relaxation" of the selective pressures that might have operated 50 or 100 years ago. "Biologically, human beings are going nowhere," says anthropologist Ian Tattersall of the American Museum of Natural History in New York City. University College London geneticist Steven Jones agrees. "The central issue is what one means by 'evolving,' " Jones says. "Most people when they think of evolution mean natural selection, a change to a different or better adapted state. In that sense, in the developed world, human evolution has stopped."

Isn't that a coincidence....

Posted by Orrin Judd at October 19, 2005 3:16 PM

The other (and more defensible) half of this silly argument is that we have only begun to evolve (using selective abortion and technology).

Which is it? Does it matter?

Posted by: Bruno at October 19, 2005 3:56 PM

What coincidence? Once a species can manipulate nature, natural selection doesn't work anymore. That's more like a truism.

Posted by: M. Bulger at October 19, 2005 4:00 PM

Yes, the truism being that one species in the Universe has freed itself from Nature. Man, you're terrible at defending what you pretend to belive.

Posted by: oj at October 19, 2005 4:08 PM

So you acknowledge that Darwinian natural selection is operative in nature?

Posted by: M. Bulger at October 19, 2005 4:12 PM

No. But whichever form of evolution each of us believes in we all think Man is its end.

Posted by: oj at October 19, 2005 4:20 PM

"...in the developed world, human evolution has stopped"

I doubt it. There seems to be significant variation in number of offspring per woman across various groups. For example, religious women seems to have more children. Thus the "God spot" will be selected for.

Posted by: Bret at October 19, 2005 6:32 PM


Are you implying that leftism is a random mutation leading to eventual extinction. OJ, this might be the most persuasive pro-Darwinist argument I've heard.

Posted by: Jeff at October 19, 2005 7:20 PM


Perhaps not exactly how I'd put it, but that's more or less what I'm saying. I've written something similar before at http://greatguys.blogspot.com/2005/03/darwinian-paradox.html

Posted by: Bret at October 19, 2005 7:28 PM


Look at Europe and the Blue States and it certainly seems that if Dawkins is right about memes then Darwinism is a deadly one.

Posted by: oj at October 19, 2005 8:54 PM

I don't think it's just a meme, but rather a meme amplified phenotype.

Posted by: Bret at October 19, 2005 9:03 PM

Well, Bret, if we assume the vast majority of European and Americans were religious in, say, the mid 19th century, don't you have the little problem of explaining how secular leftism arose in the first place? Did nature select for the non-religious for a few generations and then somehow suddenly realize what a mistake that was?

Posted by: Peter B at October 20, 2005 3:56 AM

Peter: Shame. You know that secular humanism is just another religion.

Posted by: David Cohen at October 20, 2005 8:04 AM

One particularly addicted to human sacrifice.

Posted by: oj at October 20, 2005 8:09 AM

Uh-Oh. oj, Peter B., and David Cohen are jumping on this one.

Peter, I can only make the argument about how secularism arose in the first place and then is now dwindling using Darwinism as a foundation. Since y'all believe Darwinism is hogwash, you wouldn't agree with the analysis anyway.

Nonetheless, assume Darwinism isn't hogwash for a moment. Then, it's plausible that belief in god(s) in ancient time gave some sort of advantage, perhaps for example, an organizational one. Those phenotypes pre-disposed to believe in god(s) would then be selected for. Note that since there would be a strong cultural component, they'd only need to be slightly selected for. As long as the number of people predisposed to belief in god was above a threshold, the religion meme provided the required amplification to benefit the whole society, including those not predisposed to belief in god(s).

That meme was possibly weakened with the great increase in wealth and choice and/or perhaps the invention of birth control and because the survival of the individual and/or community were no longer as dependent on the individual's conformance to societal norms including the belief in god(s). Or something like that.

Because the memetic amplification of the god(s) believing phenotype was weakened, the phenotype itself is more directly exposed to natural selection, and those not predisposed to believing in god(s) are having fewer offspring.

Posted by: Bret at October 20, 2005 12:57 PM