Evolution - Are human brains still evolving? Brain genes show signs of selection

Averaging 1350 cubic centimeters, the human brain is proportionally larger than that of any other animal. Just why natural selection blessed us with such cognive powers is poorly understood. But the fossil record and genetic studies clearly show that the evolution of higher cognition began sometime after the chimp and human lines split, some 5 million to 6 million years ago, and continued at least until the rise of modern humans, roughly 200,000 years ago. Now twonew reports suggest that the evolution of the human brain may not have stopped when Homo sapiens first came on the scene. The studies, both led by human geneticist Bruce Lahn of the University of Chicago, conclude that two genes thought to regulate brain growth have continued to evolve under natural selection until very recently and perhaps are doing so today.