American scientists from the University at Buffalo and the Jackson Laboratory have discovered the genetic origins of modern humans' ability to digest complex carbohydrate starch. This allows us to eat bread, pasta and other carbohydrate-rich foods. The study was published in the scientific journal Science.
The team analyzed the genomes of 68 ancient people, including a 45,000-year-old sample from Siberia. The analysis showed that duplication of the salivary amylase gene (AMY1), responsible for the breakdown of starch, could have occurred long before the advent of agriculture.
Amyalase is an enzyme that not only converts starch into glucose, but also gives bread its flavor.
“The idea is that the more amylase genes you have, the more amylase you can produce and the more starch you can digest efficiently,” the team explained.
Prehistoric hunter-gatherers had an average of four to eight copies of AMY1 per diploid cell.
The researchers found that duplications of the AMY1 gene occurred in Neanderthals and Denisovans. This suggests that the AMY1 gene may have first duplicated more than 800 thousand years ago, long before the separation of humans from Neanderthals and much earlier than expected.
According to the scientists, individuals with a higher number of copies of AMY1 digested starch more efficiently and had more offspring, due to which they thrived over a long evolutionary period. This property may have accelerated the separation of the ancestors of modern humans from Neanderthals and other related species.
