Not all humans have the same number of copies of the AMY1 gene. Populations which rely on carbohydrates have a higher number of AMY1 copies than populations that eat little starch. The number of AMY1 gene copies in humans can range from six copies in agricultural groups such as European-American and Japanese (two high starch populations) to only 2-3 copies in hunter-gatherer societies such as the Biaka, Datog, and Yakuts.