A new study published Thursday reveals that modern humans' worship of carbohydrates may actually predate the emergence of Neanderthals.
It has been thought that early humans needed a diet rich in protein to survive the harsh days of hunting, scavenging, and fleeing from predators. However, new research shows that Published in Science magazine We debunk this long-held belief.
The study points to a specific gene that allows humans to more easily digest starch by breaking it down into simple sugars that can be used for energy.
These genes continued to be replicated long before the rise of agriculture.
Researchers at the Jackson Laboratory in Farmington, Connecticut, and the University at Buffalo in New York studied the genomes of 68 ancient humans. The research team focused on a gene called AMY1 that allows humans to break down the complex carbohydrate starch by producing the enzyme amylase in the mouth.
Almost all modern humans have multiple copies of AMY1, but the number varies from person to person. Geneticists have struggled to pinpoint exactly how and when genes began to expand. It dates back to the time when eating starch became beneficial to human health.
“The main question we were trying to answer was when did this duplication occur? That's why we started studying ancient genomes,” said Faiza, an associate computational scientist at the Jackson Laboratory.・Yilmaz says: he told CNN.
“Previous studies have shown that there is a correlation between AMY1 copy number and the amount of amylase enzyme released in saliva. We believe that this is an event that corresponds to the emergence of agriculture. I wanted to know if that's the case. This is a hot question.
The researchers found that hunter-gatherers 45,000 years ago had about 4 to 8 copies of AMY1, which is when Homo sapiens appeared in the Mesolithic period and before the introduction of farming. Even this shows that he had the talent to obtain starch.
The study also found duplications of AMY1 in the genomes of Neanderthals and the little-known Denisovan, an extinct hominid discovered in 2010.
Multiple copies of this gene in three separate human species indicate that it was a trait shared by a common ancestor before the lineages split, according to the study.
This means that humans had multiple copies of AMY1 even 800,000 years ago.
Lacking a clear reason for the duplication, researchers believe it is likely that the duplication occurred randomly.
Over the past 4,000 years, AMY1 duplications have proliferated as humans have transitioned from a hunter-gatherer lifestyle to a starch-based diet.
Taylor Hermes, assistant professor in the Department of Anthropology at the University of Arkansas, told CNN that the study also supports existing theories that carbohydrates, rather than proteins, provide the extra energy needed for long-term increases in brain size in humans. told.
“The authors found that the copy number of the amylase gene increases, resulting in improved degradative capacity. Starch appeared hundreds of thousands of years ago, giving more credence to the idea that Neanderthals and Denisovans metabolized starch into simple sugars to facilitate the development of rapidly growing brains during human evolution. “It's possible that they did,” said Hermes, who was not connected to the study.
“This demonstrates the value of continuing to mine the genomes of our human ancestors for important medical and physiological records.”
