Monday, October 19, 2009
Are Humans Still Evolving? Absolutely, Says A New Analysis Of A Long-term Survey Of Human Health:
"There is this idea that because medicine has been so good at reducing mortality rates, that means that natural selection is no longer operating in humans," said Stephen Stearns of Yale University. A recent analysis by Stearns and colleagues turns this idea on its head....
Since large numbers of humans forgo reproduction in an evolutionary sense they might as well have died (excluding some inclusive fitness effects). If reproductive variance and heritable variation in traits correlated with that variance continues then naturally selection will be an operative phenomenon.
The paper is coming out in PNAS, so no guarantee when it'll be online, Byars, S., D. Ewbank, et al. Natural selection in a contemporary human population. Proceedings of the National Academy of Sciences, 106(42) DOI: 10.1073_pnas.0906199106.