Last month an interesting article was submitted to the Proceedings of the National Academy of Sciences regarding the acceleration of human evolution over the last 40,000 years.

Here's the abstract:
Recent acceleration of human adaptive evolution
John Hawks, Eric T. Wang, Gregory Cochran, Henry C. Harpending, and Robert K. Moyzis
Genomic surveys in humans identify a large amount of recent positive selection. Using the 3.9-million HapMap SNP dataset, we found that selection has accelerated greatly during the last 40,000 years. We tested the null hypothesis that the observed age distribution of recent positively selected linkage blocks is consistent with a constant rate of adaptive substitution during human evolution. We show that a constant rate high enough to explain the number of recently selected variants would predict (i) site heterozygosity at least 10-fold lower than is observed in humans, (ii) a strong relationship of heterozygosity and local recombination rate, which is not observed in humans, (iii) an implausibly high number of adaptive substitutions between humans and chimpanzees, and (iv) nearly 100 times the observed number of high-frequency linkage disequilibrium blocks. Larger populations generate more new selected mutations, and we show the consistency of the observed data with the historical pattern of human population growth. We consider human demographic growth to be linked with past changes in human cultures and ecologies. Both processes have contributed to the extraordinarily rapid recent genetic evolution of our species.
And the full-text:

http://www.anthro.utah.edu/PDFs/accel.pnas.smallpdf.pdf

To summarize, it says that human evolution has increased at an amazing rate since the development of agriculture, 100X faster than before that event. This means that, contrary to what was previously thought, people are much different than they were 40,000 years ago, or even 1000 or 2000 years ago.

Some recent changes: the ability to digest milk, and blue eyes in Europeans, and resistance to malaria amongst Africans.

Another interesting thing is that the people on different continents are evolving more differences, so that instead of the races becoming blended, as most people assumed was happening, they are actually diverging.

Some discussion on the subject:

http://www.reuters.com/article/healt...rpc=22&sp=true

Recent acceleration of human adaptive evolution

http://www.physorg.com/news116529402.html

http://news.nationalgeographic.com/n...olution_2.html