Gene Expression

More skepticism of natural selection

In the wake of last week’s paper, looks like another one is coming down the pipe, Hundreds of Natural-Selection Studies Could be Wrong, Study Demonstrates:

“These statistical methods have led many scientists to believe that natural selection acted on many more genes in humans than it did in chimpanzees, and they conclude that this is the reason why humans have developed large brains and other morphological differences,” said Nei. “But I believe that these scientists are wrong. The number of genes that have undergone selection should be nearly the same in humans and chimps. The differences that make us human are more likely due to mutations that were favorable to us in the particular environment into which we moved, and these mutations then accumulated through time.”

Nei said that to obtain a more realistic picture of natural selection, biologists should pair experimental data with their statistical data whenever possible. Scientists usually do not use experimental data because such experiments can be difficult to conduct and because they are very time-consuming.

Good luck on getting experimental data on humans! In any case the paper will be out in PNAS later this week. Doesn’t look like it’s on the website yet.