Question

Briefly explain how lactose tolerance in humans is an example of gene-culture evolution.

Lactose breakdown Only one-third of adults can digest milk. The rest stop making the enzyme needed to process milk sugar Prevalence of lactose intolerance 100% | 80 60 20 0 No data

Answer 1

There has existed strong positive selection pressure in isolated populations at different times so as to introduce lactose tolerance.This lactose tolerance has taken place via several independent mutations which implies the fact that adaptation to different types of milking culture had taken place.Lactase persistence did not exist in early European farmers and this is proved on the  basis of the analysis of Neolithic human skeletons, but when dairy farming started in the early Neolithic period, the frequency of lactase persistence alleles became to rise rapidly under the pressure of intense natural selection. This cultural shift towards dairy farming eventually drove the rapid evolution of lactose tolerance, making it one of the potential ecidences for gene-culture coevolution in modern humans.