Two fundamental biological mechanisms lead to the fact that the gene pool of the human population is gradually deteriorating, Alexander Markov, the famous popularizer of science, doctor of biological sciences and specialist in the theory of evolution, told Sputnik France.
The first reason is the weakening of selection against harmful mutations.
“Previously, people with illnesses, with very poor health, for the most part died, and even in childhood, in infancy, and there was a 'culling' of unfavorable mutations. And since the end of the 19th and the first half of the 20th centuries, there has been a whole revolution in the field of social security, the development of medicine, plus the solution of the problem of hunger, disability pensions, rehabilitation programs, antibiotics, and so on, and infant mortality in developed countries ultimately decreased to values, very close to zero. That is, everyone survives, and, accordingly, the selection is almost no longer working,”explained Markov.
The scientist noted that, on average, about 70 new mutations are now recorded in newborns that their parents did not have. Among them there are also neutral changes, however, there are always several mutations that can reduce the quality of the body's work, spoiling its systems or subsystems (muscles, skeleton, etc.), and - most importantly - impair the functioning of the brain.
“Hundreds, even thousands of genes must work well, harmoniously, correctly, so that we have a normally functioning brain. This means that all this will most likely hit on cognitive abilities. Our gene pool will degrade very quickly,”the biologist stressed.
This leads to the second reason for the likely deterioration of the gene pool. Large-scale studies carried out by scientists in different countries have shown that harmful genetic variants not only accumulate freely, but are supported by selection, since they allow people to reproduce better under current conditions.
“In modern society, there is such a tendency: stupid people, uneducated people (they reproduce better. - Editor’s note),” Markov said.
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 and intelligence, the biologist summed up.
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