We continue to evolve
Traces of natural selection were found in the genes of Europeans
Biologists have found out that over the past three thousand years, the structure of several hundred genes of people of European origin has changed markedly under the influence of natural selection. This confirms that human biological evolution continues, scientists write in the scientific journal Nature Human Behavior (Song et al., A selection pressure landscape for 870 human polygenic traits).
"We studied how natural selection affected 870 different features of the human body associated with several genes at once, and found that evolution affected about 88% of them. Not all changes were positive, but in most cases, selection led to a decrease in the chances of developing various diseases or increased the chances of procreation," the researchers write.
There is no consensus among scientists on whether the biological evolution of man continues after the transition to life in the conditions of civilization. Some researchers believe that after that, human development was mainly controlled by social factors, while others are confident that biological evolution Homo sapiens continues.
In a new study, Chinese biologists led by Professor Lin Guanning of Shanghai University of Transport have received confirmation of the latter thesis. They analyzed the results of large-scale genetic studies of European residents that were conducted between 2010 and 2020.
Lin and his colleagues wanted to find out how the work of several thousand genes related to human growth, predisposition to anorexia, as well as 870 other features of the body's work has changed over the past few thousand years. To do this, scientists investigated how often different mutations occur in these DNA sections of modern and ancient people who lived on Earth 4.2-14 thousand years ago.
It turned out that natural selection continues to act on the vast majority of these genes associated with 88% of the features in the appearance of a person and the work of his body. Almost all of these changes increased the adaptability of Europeans to the conditions in which their ancestors lived, and 6-7.5% of the evolutionary changes in the work of the body of men and women were associated with an increase in the chances of procreation.
Some of these changes, as biologists note, look very unusual for a modern person. In particular, mutations associated with predisposition to anorexia and intestinal diseases increased the chances of survival of their carriers. Also, earlier, carriers of gene variations associated with schizophrenia and attention deficit disorder left more offspring.
Scientists suggest that many of these mutations helped our ancestors survive in conditions of constant food shortages, frequent contacts with pathogens and other threats to life that are rare today. Lin and his colleagues hope that further research and decoding of Cro-Magnon genomes will help to test this theory.
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