A group of scientists led by Emmanuel Milo of the University of Quebec in Montreal has denied the theory that humans have stopped evolving
It is generally accepted that natural selection has ceased to play a central role in the development of humanity since the emergence of an organized society and the first technologies, but, according to recent research, this is not the case. According to some experts, natural selection has been replaced by microevolution - the accumulation of mutations in the human genome.
The study was conducted on the island of Ile aux Cudr, where the population is quite isolated, and the local church has an archive of records of the dates of birth, weddings and death of all residents. Scientists analyzed the data between 1799 and 1940. They tracked how quickly women gave birth to their first child after marriage, and how long the breaks were between subsequent births.
It turned out that the average age at which women gave birth to their first child was gradually decreasing. In 1799, he was 26 years old, and at the beginning of the 20th century - 22 years. According to the researchers, the chances of survival for all children were higher if the mother gave birth to her first child early, but the earlier a woman had her first child, the fewer children she had in her entire life. Since the first pattern is more pronounced than the second, it was possible to clearly trace the general tendency - an increase in the number of children and a decrease in the age of mothers.
By the beginning of the 20th century, the average number of children increased from 5 to 8, the authors of the article built a special statistical model, with the help of which they cut off all non-genetic factors affecting procreation. The age of birth of the first child has not lost its significance, in contrast to the general reproductive success.
Thus, the study clearly confirms that humans continue to evolve, and the consequences of microevolution are noticeable even after several generations.