Primates "made friends" with alcohol 10 million years ago
Chemist Steven Benner from the Foundation for Applied Molecular Evolution in Gainesville, Florida, came to this conclusion as a result of comparing ethanol-splitting enzymes produced by the organisms of our extinct humanoid ancestors.
The modern human body mainly breaks down ethanol contained in alcoholic beverages with the help of the enzyme alcohol dehydrogenase-4, synthesized by cells of the esophagus, stomach and intestines. This enzyme is the first to get in the way of alcohol entering the body.
To study the evolution of alcohol dehydrogenase-4, Benner and his colleagues analyzed genetic sequences encoding analogues of this enzyme in the genomes of 27 modern primate species, including monkeys, lemurs and humans. Comparing the information obtained with the primate evolution tree allowed them to reproduce the sequences of about 10 variants of the alcohol dehydrogenase gene that belonged to our ancestors, the earliest of whom inhabited the Earth about 60 million years ago. After that, the ancient enzymes were restored in the laboratory and studied.
The results of the experiments showed that most of the human ancestors could not digest alcohol. However, the situation changed about 10 million years ago – at the level of the separation of the evolutionary branch that led to the appearance of gorillas, chimpanzees and humans. At this stage, the enzyme's ability to break down ethanol has increased by about 50 times, which is practically enough for the assimilation of modern alcoholic beverages.
The authors believe that the reason for this metamorphosis was the partial transition of primates to a terrestrial lifestyle. In such conditions, the possibility of digesting fermented fruits that fell to the ground significantly increased survival. This also explains the fact of the complete inability to break down ethanol in primates living on trees, which rarely have to deal with fermented fruits.
However, according to anthropologist Jeremy DeSilva from Boston University, it is too early to draw final conclusions on this issue, since there are very few fossils at the disposal of specialists dating back to the period when humans, gorillas and chimpanzees had a common ancestor. To date, there is still debate about whether this ancestor lived exclusively in trees or spent part of his time on the ground. However, he stressed that the work carried out is of great value and in the future, when additional material evidence appears, its results will have to be re-checked.
The report of S. Benner Paleogenetics and the history of alcohol in primates was presented on February 15 at the annual congress of the American Association of Scientific Achievements.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on the materials of Science News:
Origins of alcohol consumption traced to ape ancestor.
21.02.2013