The study explores the relationship between diet and the evolution of the human amylase gene (AMY1) copy number variation. Starch consumption varies among human populations, with some groups, such as rainforest and circum-arctic hunter-gatherers, consuming significantly less starch than agricultural societies. This variation suggests that different selective pressures may have influenced the AMY1 gene, which is responsible for starch hydrolysis. The study found a positive correlation between AMY1 copy number and salivary amylase protein levels, with individuals from high-starch diets having more AMY1 copies than those from low-starch diets. This variation in AMY1 copy number is unusual and may reflect natural selection, as higher AMY1 copy numbers could improve starch digestion and buffer against the fitness-reducing effects of intestinal disease. The study analyzed AMY1 copy number in various populations, including European-Americans, Japanese, Hadza, Biaka, Mbuti, Datog, and Yakut. High-starch populations had significantly more AMY1 copies than low-starch populations. The results suggest that AMY1 copy number variation may be influenced by natural selection, particularly in high-starch populations. However, the study could not rigorously test this hypothesis due to limited comparative data. The study also compared AMY1 copy number variation with other loci in the genome, finding that the AMY1 locus showed a higher level of differentiation than most other loci. This suggests that AMY1 may have been subject to strong selective pressures. The study also compared AMY1 copy number variation in chimpanzees and bonobos, finding that humans have significantly more AMY1 copies than these primates, which may reflect evolutionary adaptations to starch-rich diets. The study concludes that diet-related selection pressures have shaped AMY1 copy number variation in humans, highlighting the importance of starchy foods in human evolution. The findings suggest that AMY1 copy number variation is a result of natural selection, particularly in populations with high-starch diets. The study also highlights the potential for other copy number variants to be subject to strong selective pressures, given their potential influence on gene expression. The study provides important insights into the evolutionary history of humans and their dietary adaptations.The study explores the relationship between diet and the evolution of the human amylase gene (AMY1) copy number variation. Starch consumption varies among human populations, with some groups, such as rainforest and circum-arctic hunter-gatherers, consuming significantly less starch than agricultural societies. This variation suggests that different selective pressures may have influenced the AMY1 gene, which is responsible for starch hydrolysis. The study found a positive correlation between AMY1 copy number and salivary amylase protein levels, with individuals from high-starch diets having more AMY1 copies than those from low-starch diets. This variation in AMY1 copy number is unusual and may reflect natural selection, as higher AMY1 copy numbers could improve starch digestion and buffer against the fitness-reducing effects of intestinal disease. The study analyzed AMY1 copy number in various populations, including European-Americans, Japanese, Hadza, Biaka, Mbuti, Datog, and Yakut. High-starch populations had significantly more AMY1 copies than low-starch populations. The results suggest that AMY1 copy number variation may be influenced by natural selection, particularly in high-starch populations. However, the study could not rigorously test this hypothesis due to limited comparative data. The study also compared AMY1 copy number variation with other loci in the genome, finding that the AMY1 locus showed a higher level of differentiation than most other loci. This suggests that AMY1 may have been subject to strong selective pressures. The study also compared AMY1 copy number variation in chimpanzees and bonobos, finding that humans have significantly more AMY1 copies than these primates, which may reflect evolutionary adaptations to starch-rich diets. The study concludes that diet-related selection pressures have shaped AMY1 copy number variation in humans, highlighting the importance of starchy foods in human evolution. The findings suggest that AMY1 copy number variation is a result of natural selection, particularly in populations with high-starch diets. The study also highlights the potential for other copy number variants to be subject to strong selective pressures, given their potential influence on gene expression. The study provides important insights into the evolutionary history of humans and their dietary adaptations.