Wednesday, February 16, 2005

93: Tracing the differences between humans and chimpanzees

Scientists find clues to 'human' genes - (United Press International):

The scientists found 22 genes, spanning about 10 percent of the human chromosome, that are duplicated in humans but not in other species. These are the most likely source of what makes humans distinctly human.
Don't get all worked up over this. It comes from the sloppy minds of the Washington Times, who suggest in that paragraph that there are 220 genes. The paper says 10% of chromosome 2 is taken up by copies of one gene.

The original paper analyzes human genes with multiple copies, which have only single gene homologues in chimps. They note that certain regions of some genes underwent positive selection. So we proceed from common descent of humans and chimpanzees and show natural selection at work, and identify macroevolutionary processes at work.