MadSci Network: Genetics |
April 1, 2001 Dear Suzanne, Up to about 3 years old humans can digest lactose because we have an enzyme called lactase. Afterwards, depending on one's alleles This process continues or ceases. Lactase deficiency is predominant among the world's people. The major hypothesis is that prior to dairy herding almost all humans were lactase deficient. Later on, in populations which long depended on dairy hearding and the ingestion of milk selection worked to the advantage of lactase sufficient individuals. In time, lactase suffient individuals increased in frequency in these populations. These populations include Europeans and Northeastern and Southern Africans. For further information see a good Physical or Biological Anthropology Textbook. Dr. Smerken
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