Is humanity involuting?
Biologist explained why the human gene pool is deteriorating
Two fundamental biological mechanisms lead to the fact that the gene pool of the human population is gradually deteriorating, the famous popularizer of science, Doctor of Biological Sciences and specialist in the theory of evolution Alexander Markov told Sputnik France.
The first reason is the weakening of selection against harmful mutations.
"Previously, people with diseases, with very poor health, mostly died, and even in childhood, in infancy, <...> and there was a "rejection" of unfavorable mutations. And since the end of the XIX and the first half of the XX century, a whole revolution has taken place in the field of social security, the development of medicine, plus the solution to the problem of hunger, disability pensions, rehabilitation programs, antibiotics, and so on, and child mortality in developed countries has eventually decreased to values very close to zero. That is, everyone survives, and, accordingly, selection almost does not work anymore," Markov explained.
The scientist noted that on average now about 70 new mutations are recorded in newborns, which their parents did not have. There are neutral changes among them, but there are always several mutations that can reduce the quality of the body's work, spoiling its systems or subsystems (musculature, skeleton, and so on), and – most importantly – worsen brain function.
"Hundreds, even thousands of genes must work well, harmoniously, correctly, so that we have a normally functioning brain. So, all this will most likely hit cognitive abilities. <...> Our gene pool will degrade very quickly," the biologist stressed.
This implies a second reason for the likely deterioration of the gene pool. Large-scale studies conducted by scientists in different countries have shown that harmful genetic variants do not just accumulate freely, but are supported by selection, since they allow people to reproduce better in the current conditions.
"There is such a trend in modern society: stupid people, uneducated people (reproduce better. – Ed.)", – said Markov.
The scientist explained that people who are genetically predisposed to grow up smart and educated leave fewer children simply because they start giving birth later. "Not much – for a year or two on average. But this is enough to create a significant selection pressure against the genes of education, intelligence," the biologist concluded.
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