Marked geographic patterns for the distribution of some heritable traits are observed in humans, including traits related to disease risk, pathogen resistance and drug response. In some cases, the ...

The unexpected discovery of a new type of genetic variation suggests that natural selection -- the force that drives evolution -- is both more powerful and more complex than scientists have thought.

We have little understanding about the evolutionary forces that influence the genes underlying complex-trait variation. Genome-wide association studies and analyses of amino-acid polymorphisms are ...