Brain shrinkage and 4 more proofs that Man continues to evolve
Categories: Health and Medicine | Science
By Pictolic https://pictolic.com/article/brain-shrinkage-and-4-more-proofs-that-man-continues-to-evolve.htmlRecent scientific discoveries have proved that human evolution has not stopped. Our genes continue to mutate, as in previous eras. But now the changes in the species are happening a hundred times faster than 10 thousand years ago. Scientists have stated that Homo sapiens is somewhere in the middle of the evolutionary chain of the human race and gave 5 facts in favor of this theory.
At the dawn of evolution, man had the ability to assimilate only mother's milk. Against the background of domestication of wild animals and the development of cattle breeding, a gene appeared in his body that is responsible for the assimilation of lactose. People who received such a mutation had a significant advantage over their fellow tribesmen. In their body, a hormone was produced to break down lactose. A varied diet helped to survive, passing the mutation to the next generations.
The gene, which first appeared in East Africa, continues to change. Today, a mutation that appeared three millennia ago has already become the norm. 95% of Europeans eat dairy products without undesirable health consequences, which cannot be said about our ancient ancestors.
Ancient people ate mostly roots, nuts, leaves, which had to be thoroughly ground in their mouths. A vegetarian diet and a raw food diet negatively affected the condition of the teeth. In response to the problem, evolution gave our ancestors wisdom teeth. They played the role of a kind of "spare", which was stored for the time being in the bowels of the body. New teeth grew when the rest had time to wear out. Thanks to the wisdom teeth, the ancient man did not die of hunger at the dawn of his strength due to caries or too hard food.
Modern food is much softer. People have learned to cook food on fire. In addition, the man armed himself with a lot of devices for grinding products. Wisdom teeth have ceased to play an important role, as the service life of other teeth has increased. We should also pay tribute to the developed dentistry, which saves us from caries, prosthetics missing teeth. Therefore, the "spare tire" does not germinate in all modern people.
In 2007, scientists from the British College Royal Holloway set out to discover new signs of the evolutionary process. To do this, they needed to study almost 1800 genes that were formed in the human genome over the previous 40,000 years. As it turned out, most of the mutations were caused by the need to resist infectious diseases. In their work, scientists have made an interesting conclusion.
The genome of Africans contains 12 previously unknown genes. The identified mutation is responsible for the protective functions of the body against malaria. The carrier of new genes gets sick less often and recovers faster in case of illness. Residents of megacities are carriers of other genes that are responsible for the body's resistance to other terrible diseases – tuberculosis and leprosy. British scientists have come to the conclusion that the place of residence has a decisive influence on mutations of genes responsible for the formation of immunity.
A large brain allowed a person to occupy the top step of the evolution of the living world on the planet. Scientists note a steady tendency to reduce the volume of gray matter. The brain of primitive people had a volume of 1,500 cubic centimeters. Over the previous 30 thousand years, this figure has decreased to 1,350 cubic centimeters. The brain of modern people is 150 cubic centimeters smaller than that of ancient ancestors. Which is approximately equal to the volume of a tennis ball.
Scientists offer several theories that explain the reason for the reduction in the volume of gray matter. Firstly, we think less and gradually become stupid. Such luxury has become available thanks to the complex organization of modern society in general and the high standard of living of each individual in particular. Simply put, we don't have to be smart at every step to survive.
Secondly, a small brain turned out to be much more efficient than a large one. Neural connections are easier and faster to implement in a compact volume. This allows you to successfully adapt to new conditions, quickly acquire the necessary skills. Scientists also tend to believe that a small brain increases social skills, allowing a person to interact effectively in a team.
According to the principle of the dominant gene, humanity should have become brown-eyed long ago. A hundred millennia ago, the first blue-eyed man appeared in the Black Sea region. Scientists cannot explain why the recessive gene has spread and survived to the present day. For unknown reasons, the blue eyes gene is not just set up for survival. He also programs media.
According to a 2007 study, people with light eyes gravitate towards each other. Blue-eyed girls and boys are more likely to sympathize with representatives of the other sex with light eyes. Brown-eyed people do not demonstrate such integrity.
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