Human culture can be force for evolution, says this New York Times article. The prime example cited is lactose tolerance in adults of northern European and some of African descent — being able to consume that added source of nutrition, it is thought, allowed people with that ability to better survive and pass that gene on. Now, the article says, researchers are scanning through the human genome to find regions under selective pressure. One finding from that is that the genomes of people living in agrarian societies contain extra copies of amylase — perhaps because they eat more starch. Another gene under selection is EDAR, which is involved in controlling hair growth and a variant of which is more common in East Asian and Native American populations. The reason why EDAR is under selection is not yet known but theories include heat retention from thicker hair, sexual selection, or as a tag-along feature, as EDAR is also involved in the immune system.
Culture as a Selective Force
Mar 04, 2010