Chau TranJoshua NoyerANT 0014/15/14ANT Essay OutlineIntro: Importance of the purpose: The study of lactose tolerance is one of many that shows natural selection. Thesis: Humans from only some populations can tolerate milk because of their genetic history, milk tolerance in adult humans arose because of a mutation, homo neanderthalensis would not be able to digest milk as adults, and if a population was to stop drinking milk due to increased availability of other foods, they would eventually become lactose intolerant.Body:Why can individuals from only some human populations tolerate milk as adults? Mutations Environmental exposureIn your own words, describe in detail the genetic changes that allow for milk tolerance in adult humans. Mutations in gametes allowed the gene to be passed onto offspring Most likely an activator or inhibitor mutationWhat do these genetic changes tell us about the evolutionary history of milk tolerance in human populations? Milk tolerance arose when cattle were domesticated (first case in China)Based on your knowledge of milk tolerance in humans, would you expect that Homo neanderthalensis individuals were able to tolerate milk as adults? Homo neanderthalensis are lactose intolerant No exposure to milk No domesticated cattle No benefit from having the gene that makes lactaseWhat would you expect to happen if a population stopped drinking milk due to the increased availability of other foods? Over time, the population becomes lactose intolerant No longer a need for milk