“Still Evolving, Human Genes Tell New Story”, by NICHOLAS WADE, March 7, 2006

“There is ample evidence that selection has been a major
driving point in our evolution during the last 10,000
years, and there is no reason to suppose that it has
stopped,” said Jonathan Pritchard, a population
geneticist at the University of Chicago who headed the
study…

Their data is based on DNA changes in three populations
gathered by the HapMap project, which built on the
decoding of the human genome in 2003. The data, though
collected to help identify variant genes that contribute
to disease, also give evidence of evolutionary change…

Dr. Pritchard estimates that the average point at which
the selected genes started to become more common under
the pressure of natural selection is 10,800 years ago in
the African population and 6,600 years ago in the Asian
and European populations.

Skeletons similar in form to modern Chinese are hard to
find before that period, Dr. Klein said, and there are
few European skeletons older than 10,000 years that look
like modern Europeans.

Dr. Pritchard’s list of selected genes also includes
five that affect skin color. The selected versions of
the genes occur solely in Europeans and are presumably
responsible for pale skin. Anthropologists have
generally assumed that the first modern humans to arrive
in Europe some 45,000 years ago had the dark skin of
their African origins, but soon acquired the paler skin
needed to admit sunlight for vitamin D synthesis.

The finding of five skin genes selected 6,600 years ago
could imply that Europeans acquired their pale skin much
more recently.

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.”