Decrease in testosterone levels in ancient man 50 thousand years back served as the beginning of the development of culture and sociability. it it was reflected in the structure of skulls, the superciliary arches also decreased overall, the upper part of the face has become shorter.
A photo from open sources
According to official science, modern man (Homo sapiens) arose as a species about 200 thousand years ago, but only 50 thousand years back he had a sharp jump in the development of culture and technology. New tools have appeared.
“A model of modern human behavior aimed at searching new technologies, the development of art and cultural exchange, judging by everything arose just when a person learned interact with oneself in a more peaceful way. When learned to negotiate, “says biologist Robert Siri (Robert Cieri) from Duke University.
A recent study led by Siri was published in Current Anthropology Magazine. Comparative measurements of 1400 modern and ancient human skulls: 13 skulls 80 thousand years old, 41 skull aged 10 to 38 thousand years and 1367 skulls of people living in the 20th century from 30 different ethnic groups.
As a result of measurements, a trend with a significant a decrease in the size of the superciliary arches and a general shortening of the upper parts of the face. The skull has also become more rounded. All this can be connected with a decrease in testosterone levels. Roughly speaking, facial features in more “young” skulls were more “feminine” than more the ancients.
A photo from open sources
Skulls began to change about 50 thousand years ago (upper Paleolithic) and then there was a sharp jump in the level of development culture of mankind. Bone tools abounded heat treatment, silicon knives, throwing weapons and a variety of household items like grindstones or appliances for fishing. Apparently due to a drop in testosterone levels, which is closely associated with aggressive behavior, people have become kinder to each other, learned to negotiate and make cultural exchange.
Another research group at Duke University, which working with animals, confirmed these observations and addressed their four-legged wards. Domestication of Siberian fox when by the most non-aggressive individuals were selected (low level testosterone), showed that modern animals are also different and appearance and behavior.
Professor Brian Hare studied the differences between ordinary chimpanzees and bonobo chimpanzees. Ordinary more aggressive bonobos, on the contrary, are more humble and loving. The difference is that in puberty in male chimpanzees rises sharply testosterone levels, but bonobos do not.
What could cause a significant drop in testosterone levels in ancient men?
– It is possible that this happened when the number of people grew to a certain critical point and they involuntarily had to learn to get along with each other. – suggests Siri.
Testosterone is the main male sex hormone. Animal experiments show that it strongly affects aggressiveness, sexual behavior, anxiety, learning, as well as those parts of the brain and neurotransmitters on which the corresponding reactions depend.