“Humans who continued lactase production were more likely to suffer when meat and plant material were unavailable. Genetic testing indicates that lactase persistence evolved separately among subgroups of Europeans and Africans, illustrating the strong environmental pressure for phenotypic processing of milk products based on cultural practices. In culture that do not practice dairy farming, such as many areas of Asia, lactase persistence is low.” EvolutionIntoleranceDairyEnzymeLactaseSugars Book:A Guide to the Psychology of Eating Source: A Guide to the Psychology of Eating