Humans may have developed the ability to begin digesting these foods in the mouth long before they began farming and perhaps even long before the appearance of modern humans, namely us. Research has found that the gene for starch-digesting saliva may have first been duplicated more than 800,000 years ago, setting the stage for the genetic change that shaped diet us today.
Duplication is a type of mutation that involves the production of one or more copies of a gene. Experts have known for some time that people carry multiple copies of a gene that allows the starch in complex carbohydrates — which also include foods like potatoes, rice and some fruits and vegetables — to begin breaking down in the mouth.
This provides the first step in digesting these foods, and the more copies of these genes people have, the better equipped they are to break down carbohydrates. However, it has been difficult for researchers to determine how and when the number of these genes expanded.
The news to study led by the University at Buffalo and the Jackson Laboratory in the US, found that the genetic duplication – known as the salivary amylase gene (AMY1) – may not only have helped shape human adaptation to starchy foods, but may have occurred before of more than 800 thousand years, long before the birth of agriculture, which dates back only seven thousand years.
The enzyme
According to scientists, amylase is an enzyme that not only breaks down 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,” says Omer Goksumen, professor in the department of biological sciences in the College of Arts and Sciences at the University at Buffalo. .
Analyzing the genome of 68 ancient humans, including one sample DNA At 45,000 years old in Siberia, researchers discovered that pre-agricultural hunter-gatherers already had duplicate copies of the gene. This suggests that humans were already roaming Eurasia with a wide variety of these genes long before they began domesticating plants and eating excessive amounts of starch. The study also found that duplications of the AMY1 gene appeared in both Neanderthals and the mysterious Denisovan hominin discovered 20 years ago.
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