structural:summarization, linguistic:translation
Evolutionary advantages

The ability to digest fresh milk through adulthood is genetically coded for by different variants which are located upstream of the LCT gene and which differ among populations. Those variants are found at very high frequencies in some populations and show signatures of selection. There are two notable hypotheses with dissimilar theories which try to explain why lactase persistence phenotype has been positively selected. The first one, known as the cultural-historical hypothesis, states that the main reason for LP is the introduction of dairy-based food products into the diet, while the reverse-cause hypothesis argues that dairy consumption was embraced by the societies which were already high in LP frequency.