More selection for chimp genes

Study claims more chimp genes than human underwent adaptive evolution

Melissa Lee Phillips
Apr 16, 2007
More chimpanzee genes than human genes have gone through positive Darwinian selection, according to a study published online this week in the Proceedings of the National Academy of Sciences. The authors propose that natural selection has been more effective in chimpanzees because they have had larger effective population sizes."The results are really important if they're true, because I think they reverse our bias that natural selection has operated more aggressively on humans," said David Reich of Harvard University in Cambridge, Mass., who was not involved in the study.Previous studies have looked for positively selected genes in chimpanzees and humans, "but they never compared the numbers between the two species," said senior author Jianzhi Zhang of the University of Michigan in Ann Arbor.Led by Margaret A. Bakewell, also of the University of Michigan, the researchers adjusted previous methods of measuring positive selection to correct "potential biases and make...