Darwinian evolution means different things to different people. To me, and many other population geneticists, it refers to positive selection. To Jeffrey Schwartz, an anthropologist at the University of Pittsburgh, Darwinian evolution means gradual change. By the way, Schwartz also thinks humans are more closely related to orangutans than they are to chimps and gorillas.
I'm having a hard time making heads or tails of Schwartz. He seems hypercritical of all molecular evolution -- to the point where one wonders whether he even understands the field. He appears to not understand that evolution at different levels (DNA sequence, protein sequence, cellular, anatomical, etc) can occur at different modes and tempos. Many DNA mutations are neutral -- they confer no phenotypic effect and no fitness benefit or cost -- and these changes are remarkably useful for inferring evolutionary relationships. When looking over short time scales (millions of years), DNA sequences can be used reconstruct phylogenies because they evolve quite rapidly. But protein sequences are more useful over longer time scales (tens to hundreds of millions of years) because they evolve slower.
Furthermore, when one looks at different time scales, the gradual nature of evolutionary change manifests itself at different evolutionary levels. One would struggle to find evidence that amino acid sequences evolve gradually within a species or between closely related species. There simply aren't enough changes over this short time scale, and when we do see a lot of changes they are examples of evolutionary bursts. But DNA sequences do evolve gradually at this time scale. Schwartz seems to not understand these important points.
- Log in to post comments
More like this
When the controversy emerged, we had emails saying we should read Schwartz's paper. When we finally did, nobody even did say anything. When graduate students did, not even a single one had anything to add. That's it... There is nothing to add. Let's do science.
Jeffrey Schwartz was on Rod Liddle's "documentary" The Trouble with Atheism.
He made an ass of himself, but I figured that was mostly Liddle's creative cutting. I guess I gave Schwartz too much credit.
This is the same Jeffrey H. Schwartz who wrote "Sudden Origins" one of the worst popular science books that's ever been published. When it first came out we had a field day in talk.origins demonstrating exactly how ignorant Schwartz was about all things scientific. He didn't even understand the difference between dominant and recessive alleles, for example.
He quoted from papers on HOX genes referring to conclusions that were the exact opposite of what the authors actually said. In short, he's totally incompetent but far too stupid to recognize his ignorance.
I don't understand how people like that can get tenure at a major university.
"When graduate students did, not even a single one had anything to add." --Laurent
Your post is somewhat ambiguous. Were you and the grad students awed into a profound silence? Was Schwartz's work so air-tight that there was nothing to criticize?
The notion that humans are more closely related to orangutans than chimps is absurd when considering molecular data. So I would think there would be a good bit to say about anything this fellow has written concerning the molecular world.
When there are too many things to say, it just means it's no use to say anything. Precious time has many uses but being lost... That's it.