New research published in Science suggests a significant link between the number of copies of the AMY1 gene, responsible for starch digestion, and the dietary habits of ancient hominins and modern humans. This study highlights how the ability to process starches evolved, potentially driven by the advent of cooking and later, agricultural practices.
Researchers examined eight ancient genomes, discovering multiple copies of the AMY1 gene in select Neanderthal, Denisovan, and early human samples. The variability in AMY1 copy numbers is believed to have originated before the divergence of these groups. This suggests an early adaptation to dietary changes, possibly linked to the use of fire and the consumption of cooked starches.
Furthermore, the study indicates a clear trend: as human societies transitioned from hunter-gatherer lifestyles to agricultural ones, the number of AMY1 copies in their genomes increased. This adaptation, researchers propose, stems from the need to process the higher carbohydrate intake associated with farming and grain-based foods.
Interestingly, genomes from pre-agricultural individuals showed a range of four to eight copies of AMY1, indicating some degree of starch processing before the development of agriculture. The study showed, however, a clear increase in AMY1 copies after the advent of agriculture, with further increases in the last 4,000 years. Modern humans now possess between two and fifteen copies.
This research underscores the evolutionary impact of dietary changes on human genetics. It also offers a potential avenue to investigate the correlation between AMY1 gene variation and metabolic conditions such as gluten allergies and celiac disease. In addition, the study explains how AMY1 influences not only how humans digest starches but also how they taste, potentially shaping carbohydrate preferences. The findings offer valuable insight into the complex relationship between genetic heritage and human dietary habits.
