Evolution and Natural Selection
Explanation:
Salivary amylase gene (AMY1) copy number is correlated positively with salivary amylase protein levels, and that individuals from populations with high-starch diets have on average more AMY1 copies than those with traditionally low-starch diets. Higher AMY1 copy numbers and protein levels likely improve the digestion of starchy foods, and may buffer against the fitness-reducing effects of intestinal disease.
Chimpanzees did not feed much on starchy food and thus had only diploid copies of AMY1 gene. However, humans have 6-15 copies of AMY1 gene because of high consumption of starchy food. Therefore, as the evolution of chimpanzees occured, humans adapted itself to what changes in their habitat.
