Over the last 40,000 years it seems our human bodies, inside and out, have been rapidly evolving. Genomic technology has been a huge help in showing scientists that we have been evolving quicker, and not slowed down in the least.

   Henry Harpending is a research team leader and distinguished professor of anthropology at the University of Utah.

"We aren't the same as people even 1,000 or 2,000 years ago," he says, which may explain, for example, part of the difference between Viking invaders and their peaceful Swedish descendants. "The dogma has been these are cultural fluctuations, but almost any temperament trait you look at is under strong genetic influence."

   A large chunk of the reason is quite possibly due to the explosive growth in the human population. Humans have had to adapt quickly to a surrounding that is constantly upgrading and changing.