How can one explain the unusually rapid evolution of man in the last two million years?
"War is the father of all, the king of all: she declares some as gods, others as people, some as slaves, others as free." (Heraclitus)
Ian Tattersall of the American Museum of Natural History, one of the leading experts in the field of human origins, proposed a new answer to this question at the Calpe conference.
The tachithelium of the human race is characterized primarily by the fact that the brain volume of our ancestors doubled between 1 and 2 million years ago and then, between 1 million years ago and the present, did it again. At the same time, there was a decrease in the teeth and face, and the whole skull changed noticeably.
The increase in brain size seems to coincide with the emergence of the modern human anatomical structure, that is, slenderness, long legs and relatively narrow hips. These features are already possessed by the skeleton of the "Turkan boy" who lived in Kenya about 2 million years ago. In contrast, its progenitor "Lucy" (Australopithecus afarensis), who lived in Ethiopia a million years earlier, had short legs and long arms.
Nothing like this has been seen among great apes, and Mr. Tattersall believes that the dramatic lifestyle change when our ancestors descended the trees (which other primates never did) played a major role in such dramatic changes. “Obviously, the decisive rejection of life in trees should be considered one of the most radical shifts in the adaptive zone of vertebrates since the time of the first four-legged to get out of the water on solid ground,” the scientist said.
But this factor alone is clearly not enough. “It is difficult to explain by natural laws how the invasion of the new ecozone by hominids led to such rapid changes,” the specialist emphasizes.
Culture has become the new driving force behind evolution. But, according to Mr. Tattersall, her role is being overestimated. Several evolutionary psychologists have popularized the model in which culture and brain complication spur one another on. But this is contradicted by the fact that technical progress went in fits and starts and, moreover, did not correspond to biological evolution.
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Instead, the researcher proposes the hypothesis of hostility between small human groups as the main reason for changes after adaptation to a new habitat. In his opinion, it was the constant conflicts that led to the fact that natural selection began to win the smartest individuals able to plan their actions. That is why for some time the first thing in the representatives of the genus Homo was changing the brain volume.
This behavior can be compared with the relationship between a predator and a prey. Thus, Mr. Tattersall's idea fits into the Black Queen's hypothesis, which assumes a constant arms race between predator and prey.
Despite the meager human remains, there are hints of conflict. So, recently it became known that the ancient people who lived in the north of Spain, ate representatives of another group.
The final picture is as follows. Cultural and technological progress should not be written off: clothing, housing, the use of fire allowed people to live in conditions that unprotected bodies could not withstand. But culture and technology are not omnipotent, and the settlement of people nevertheless took place in step with the improvement of climatic conditions. Then ice and deserts again began to take their own, and relatively large groups of people inevitably broke up into smaller ones, and each, naturally, developed its own biological characteristics. When it became easier to live at the next turn of the climatic spiral, once isolated groups met, and the strong either exterminated or assimilated the weak. Thus, traits that were initially possessed only by the most fortunate groups became the property of all mankind. With the deteriorating climate, everything repeated itself once again.
And in the Pleistocene (2.5 million - 11 thousand years ago), the planet's climate changed especially sharply and often …
