Adapting to Arsenic
Andean communities may have evolved the ability to metabolize arsenic, a trait that could be the first documented example of a toxic substance acting as an agent of natural selection in humans.
http://www.the-scientist.com//?articles.view/articleNo/43019/title/Adapting-to-Arsenic/
Really interesting article showing the power of evolution is with us even today, though as a biochemist in the laboratory I have seen proof of evolution many times in the past. Earlier I have blogged about arsenic and some research that initially was dramatically interesting, but then proved to be poor lab technique (lay people might be disappointingly shocked to learn how often that happens and this is far from the only case that made it through peer review and into publication). It is feasible this research won’t stand up to scrutiny, but such is the nature of science. It is an interesting topic, I have to imagine someone will want to try and reproduce the results.