American geneticists, led by Bruce Lahn, Doctor of Biology, published a sensational work in which they argue that mutations occur in the human brain, which may lead to the emergence of a new race
Scientists tried to explain the mechanism of an increase in the human brain - after all, it is known that if the brain of Australopithecus weighed only 500 g, then in Pithecanthropus its size was already twice as large, and in a modern man 5500 years ago, when evolution ended, the brain weight stopped at one and a half kilograms.
Scientists say that the size of the brain depends on 20 different genes. After examining two of them, microcephalin and ASPM, they found that natural selection mutated these genes. Calculations showed that microcephalin began to actively change about 37 thousand years ago, when our ancestors began to draw on the walls of caves, make stone tools and speak clearly.
And the ASPM gene began to mutate about 5 and a half thousand years ago, when writing appeared on Earth. Thus, American scientists came to the conclusion that changes at the genetic level begin to occur when a person invents something fundamentally new.
Therefore, we can assume that due to the powerful development of technology, today humanity is on the verge of a new evolutionary leap, to which our brain will again respond with an increase in volume.
The earliest representatives of the human evolutionary line - Australopithecus - had a brain no larger than that of modern apes (approximately 400-450 cc). About 2 million years ago, it began to gradually increase and grew sharply (up to 1000 cubic centimeters) in the early archantropians (Homo ergaster / Homo erectus). The second period of rapid brain growth (up to 1300-1500 cc) falls on a time between 500 and 200 thousand years ago, that is, during the formation of the two most advanced species that crown the evolutionary tree of hominids: Homo sapiens and Homo neanderthalensis.
The dramatic enlargement of the brain in early archantropians was traditionally associated with an increase in the consumption of meat food. Indeed, there is direct archaeological evidence that meat played a prominent role in the diet of the archantropians. Whether they were skillful hunters or just collecting carrion - this issue is actively debated, but the fact remains: they really dragged animal carcasses or parts of them to their sites and scraped the bones with their stone tools.
But is it only meat? In 1999, it was hypothesized that the early archanthropus, who appeared about 1.9 million years ago, already knew how to cook food on fire, which made it possible to dramatically reduce the costs of the body for its assimilation (see Wrangham RW et al. 1999. The Raw and the Stolen. Cooking and the Ecology of Human Origins). The hypothesis was based on indirect evidence. For example, on the fact that early archantropians increased not only the brain, but also the overall size of the body. In addition, their teeth have decreased. This means that they now had to work less with their jaws.
By comparison, chimpanzees spend an average of 5 hours a day chewing, while modern hunter-gatherers who cook food on fire only spend one hour.