Forget evolution. Think about how the characteristics of domestic animal breeds can be changed in a single decade through selective cross-breeding. The problem with the whole topic, however, is that - at present - it’s a true dismal science (unlike economics, which is neither truly dismal nor a science). There’s not much that can be done about a person’s essential characteristics once he’s born. Calvin was right, but with genes being the mechanism of divinely-ordained determinism.
I don’t believe anyone raises an argument when it is pointed out that people who have lived at high altitudes (Andes, Himalayas) over generations developed a tolerance for low oxygen levels, or those who have lived in malarial environments developed red blood cells with the sickle cell trait (see http://www.cdc.gov/malaria/about/biology/sickle_cell.html) as a protective advantage.