Human Brain Still Evolving

Forbes.com ^ | 9/8/2005 | Alan Mozes

[Mike Bates]

The evolution of the human brain is not quite a done deal, say researchers who've uncovered genetic evidence that man's mysterious gray matter is still undergoing beneficial change.

The scientists make their claim based on the recent evolutionary history of two genes -- microcephalin and abnormal spindle-like microcephaly-associated (ASPM) -- which appear to regulate brain size.

Over thousands of years, both genes seem to be generating new and improved versions of themselves -- beneficial mutations that are spreading rapidly among the human population to reshape and strengthen brain capacity.

"I think a lot of people might consider humans to be at the pinnacle of evolutionary lineage -- that we have achieved an advanced state as a species, and we have basically become the end-game," said study co-author Bruce T. Lahn, a Howard Hughes Medical Institute investigator and assistant professor of human genetics at the University of Chicago. "But what we found indicates that the species -- particularly when it comes to the brain, which is perhaps our most defining feature -- is still evolving."

In the Sept. 9 issue of Science, Lahn and his colleagues report on the results of two genetic analyses -- the first conducted among 90 men and women and a chimpanzee, and the second among almost 1,200 men and women. The participant pools were drawn from 59 ethnic groups from all over the world.

[Dajjal]

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