It’s no surprise that natural selection does not always take an evolutionary time scale.
When thousands of knights died during the Crusades at Acre, natural selection was being channeled. Yes, there were still other mechanisms of evolution but when the available pool of people is changed, positive selection is changed also.
Pinpointing that on a time scale can be tough but there has been much research into the factors that have influenced the human genome since the end of the last Ice Age and a team of anthropologists, geneticists and archaeologists have analyzed ancient DNA from skeletons and found that selection has had a significant effect on the human genome even in the past 5,000 years.
Read the full, original story: 5,000 Years: Recent Natural Selection Altered The Appearance Of Europeans
