An article in today's New York Times says that humans have been evolving during the past 15,000 years:
Providing the strongest evidence yet that humans are still evolving, researchers have detected some 700 regions of the human genome where genes appear to have been reshaped by natural selection, a principal force of evolution, within the last 5,000 to 15,000 years.
Furthermore, the different races have been evolving differently:
Three populations were studied, Africans, East Asians and Europeans. In each, a mostly different set of genes had been favored by natural selection.
Some of the genes only affect physical appearance:
The selected genes, which affect skin color, hair texture and bone structure, may underlie the present-day differences in racial appearance.
But much more interesting, genes that affect the brain have also been evolving, and they have also been evolving differently in the different populations:
Dr. Pritchard also detected selection at work in brain genes, including a group known as microcephaly genes because, when disrupted, they cause people to be born with unusually small brains.
Dr. Bruce Lahn, also of the University of Chicago, theorizes that successive changes in the microcephaly genes may have enabled the brain to enlarge in primate evolution, a process that may have continued in the recent human past.
Last September, Dr. Lahn reported that one microcephaly gene had recently changed in Europeans and another in Europeans and Asians. He predicted that other brain genes would be found to have changed in other populations.
Dr. Pritchard's test did not detect a signal of selection in Dr. Lahn's two genes, but that may just reflect limitations of the test, he and Dr. Lahn said. Dr. Pritchard found one microcephaly gene that had been selected for in Africans and another in Europeans and East Asians. Another brain gene, SNTG1, was under heavy selection in all three populations.
"It seems like a really interesting gene, given our results, but there doesn't seem to be that much known about exactly what it's doing to the brain," Dr. Pritchard said.
Dr. Wells said that it was not surprising the brain had continued to evolve along with other types of genes, but that nothing could be inferred about the nature of the selective pressure until the function of the selected genes was understood.
The article mentions how some of these brain genes (microcephaly genes) affect brain size. This immediately made me think of the research of J. Philippe Rushton. Rushton measured cranial capacity of the different races and discovered that Asians have larger brains than whites, who have larger brains than blacks.
Racial IQ differences have long been a taboo topic, but perhaps modern genetics will force the taboo to be broken, because it now looks like individual brain genes that differ between the races are being discovered.