Our ancestors were generalists.
Scientific fact: the brain of the people of the Upper Paleolithic (40−12 thousand years ago) and even the brain of Neanderthals (the last of them lived 40 thousand years ago) was larger than the brain of modern man. In late Neanderthals its volume reached 1500 cm ³ and more. In men of the twenty-first century, the average brain size is approximately 1425 cm³, in women – 1350 cm³.
Since the late 1980s, scientists have been looking for the reasons for these changes, which the language does not turn to be called evolutionary. After all, we are accustomed to be proud of our “rationality” and are convinced that it was the developed brain that lifted Homo sapiens to the top of evolution and created the crown of nature out of it.
“The decrease in the brain began about 25 thousand years ago and quite significantly continued for about 10 thousand years,” says the scientific editor of the portal anthropogenesis.ru, an associate professor at the biological faculty of Moscow State University. Lomonosov Stanislav Drobyshevsky. – It plunges many into confusion: were the ancient people smarter than us? How so? After all, they had a lower, primitive culture! But let's imagine the difficult conditions in which our distant ancestors lived. And how much knowledge and information they had to keep in their head: how to make tools, how to make fire, how to build a home, how to track down prey and how to catch it, gut it, prepare what you can eat and what not, how to protect yourself from predators or parasites? And remember the myths and legends. And all this in one head! Without exaggeration, they were generalists. ”
Modern man gets everything ready – and food, and clothing, and information. Looking at the young representatives of the generation Z, we can assume that they are already born with iPhones in their hands.
Ask a citizen to personally build, for example, an ax. The result is predictable. At best, we are ready to assemble IKEA furniture with our own hands, where all the screws and holes are already perfectly matched to each other.
Despite the fact that the civilization rushed forward, and the total amount of information acquired and accumulated by people reached astronomical magnitudes, knowledge in the head of a single person noticeably diminished. We can not say that we are more stupid than our ancestors. It was just that they needed to constantly work with their brains and comprehend the world around them through their own experience.
How does a man look like a pet?
The brain is an extremely energy-intensive organ. It accounts for only 2% of the mass of the human body, and it consumes 25% of energy. Including for this reason, the ancient people had a powerful physique: they needed to feed the contents of the cranium hard, harvesting the meat of wild animals for hunting.
Then Homo sapiens mastered farming, his life became more stable and simpler, and the size of the brain began to decrease. Moreover, this process, according to biologists, was supported by natural selection.
The price for the weaker sex was now not firmly built males, but individuals with increased fertility. And in order to leave more offspring, large dimensions are not needed. Demand began to enjoy not aggressive, but friendly individuals, and their physical parameters are less.
By the way, modern peoples, who are descendants of nomadic pastoralists, have a slightly larger average brain size than, for example, Europeans. These are the Mongols, the Buryats, the Kazakhs. The reason is that their ancestors continued to eat high-calorie animal food, while farmers switched to a carbohydrate diet. Though the size of a brain was reduced and at them.
Scientists call this brain shrinking effect “domestication syndrome” – by analogy with domestic animals. Studies have shown that in animals tamed by man, not only the behavior and hormonal background, but also the volume of the brain changes with time. That's right, it becomes smaller compared with the brain of their wild "brothers." A full and quiet life has for this – after all, the brain is not only energy-intensive, it is also lazy.
How to increase synapses
Well, what about mental abilities? Are they somehow related to the size of the brain?
“Directly within a biological species, no,” states Stanislav Drobyshevsky. – Intellect basically does not depend on the size of the brain, or even on the number of neurons in it, but on the number of connections between neurons. And it may be due to heredity, determined by lifestyle or experience. If a person is constantly learning, he develops more and more such connections – his intellect will be higher ”.
In addition to the number of connections between neurons (they are called synapses), other nuances play a role – the ability to transmit impulses, the speed of this transmission and much more.
It is noteworthy that with age, the number of neurons is significantly reduced, however, the human intellectual abilities can remain the same or even increase. This is when new synapses grow in the brain.
What is waiting for humanity next? Will our brain continue to shrink? The population is growing, specialization is increasing (everyone learns a certain area of knowledge and specific skills), besides, we constantly strive to facilitate our lives with all sorts of civilization achievements and protect ourselves from poor environmental conditions. And all this prerequisites for further reduction of the brain.
Or would you like to live in a cave, but with a large brain?
See also: Alternating current helped to improve memory.
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