The evolution of lactase persistence

Evolution of Lactase Persistence

Though humans are known to lose lactase ability post-weaning, some people maintain lactase production into adulthood, a condition known as lactase persistence. Global distribution patterns of lactase persistency are inconsistent; the condition is much more prevalent in some populations than others. Using results across independent studies, the existence of such a phenomenon can be attributed to...

THE ORIGINS OF LACTASE PERSISTENCE AND ONGOING CONVERGENT EVOLUTION by

Evolution of lactase persistence: an example of human niche construction.

Niche construction is the process by which organisms construct important components of their local environment in ways that introduce novel selection pressures. Lactase persistence is one of the clearest examples of niche construction in humans. Lactase is the enzyme responsible for the digestion of the milk sugar lactose and its production decreases after the weaning phase in most mammals, inc...

Lactase persistence in central Asia: phenotype, genotype, and evolution.

The aim of the present study is to document the evolution of the lactase persistence trait in Central Asia, a geographical area that is thought to have been a region of long-term pastoralism. Several ethnic groups co-exist in this area: Indo-Iranian speakers who are traditionally agriculturist (Tajik) and Turkic speakers who used to be nomadic herders (Kazakh, Karakalpak, Kyrgyz, Turkmen). It w...

Molecular Genetics of Lactase Persistence

This thesis is based on the following original articles, which are referred to in the text by their Roman numerals. In addition, some unpublished data are presented Assignment of the locus for congenital lactase deficiency to 2q21, in the vicinity of but separate from the lactase-phlorizin hydrolase gene. Identification of a variant associated with adult-type hypolactasia. Transcriptional regul...