Scientists: the meat, not the ability to cook food, motivated human evolution – RIA Novosti

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© AP Photo / Mark Thiessen / National Geographic via AP

MOSCOW, March 10 – RIA Novosti Go to meat diet and. the invention of tools, rather than the opening of the cooking allowed our ancestors to abandon the powerful jaw apparatus and significantly reduce energy consumption for chewing food, which served as the impetus for the evolution of our species, according to a paper published in the journal Nature.

“When there was a race of Homo, our ancestors lost large elongated snout, and large teeth and acquired flat face and small teeth. These changes, as well as several other adaptations have allowed the evolution of man began to push in the direction of increasing brain size and the acquisition of speech. The reason for all this was the simplest of the known technology – the ability to cut the meat into small pieces and mash the vegetables, “- said Daniel Lieberman (Daniel Lieberman) from Harvard University (USA)

How to tell paleontologists about 3. 2.5 million years ago our ancestors lived through a real food revolution in the transition from Australopithecus to the first of Homo. It is accompanied by a marked decrease in the size of the teeth, jaws miniaturization and the reduction of the masticatory muscles, intestines and simplification, as the isotope analysis of teeth, a noticeable shift in the diet.

Today, among scientists there is no consensus as to why this happened. some anthropologists believe that the reason for such a “revolution” and the beginning of human evolution on the current scenario was that our ancestors began to cook on the fire, which dramatically increase its nutritional value and digestibility, while others believe that the reason for this growth was the transition to a meat diet.

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Lieberman and his colleagues tested which of these hypotheses is correct, with an unusual experiment in which scientists were forced to volunteer to chew pieces of various plant and animal food by measuring the effort that they spent on chewing food.

Looking at this process and making small modifications “paleodietu” volunteers , the authors found that simply cutting food into small pieces without her cooking and adding to the diet even small amounts of meat dramatically reduces the effort and time that people have to spend on food chewing.

For example, the transition to partial meat diet, in which the proportion of meat is only third in the chewing of food decreases energy costs by more than 20%. Interestingly, a similar effect was observed only in the event that eaten by raw meat was cut into small pieces. Otherwise, the meat turned into a kind of “gum”

This means, according to Lieberman and colleagues that human evolution at the dawn of the genus Homo and the gradual reduction in the size of our teeth and jaws were due to two factors -. A transition . on a meat diet, and the invention of tools that allowed our ancestors to cut the meat into pieces and mash vegetables

Such a conclusion, as expected, do not be persuaded supporters “culinary theory” – in its favor says several fossil and genetic evidence We are talking about the fact that our ancestors began to cook already 1.5-1.8 million years ago, and that the growth of the brain has been “sponsored” starch and other carbohydrates that occur when cooking vegetable products.