Negative selection by intelligence level
Geneticists have proved that smart people are doomed to extinction
Observations of the life of Icelanders and analysis of their DNA helped scientists to prove the popular idea that a tendency to learn and a high level of intelligence negatively affect the prospects of procreation, according to an article published in the journal PNAS.
In recent years, scientists have been actively trying to find genes and mutations associated with the development of autism, schizophrenia and other brain problems, as well as variations in genes that are associated with abnormally high or low intellectual abilities. Scientists find similar "typos" in DNA by comparing the structure of genes in several hundred thousand and even millions of people.
Relatively recently, as Kari Stefansson from the deCODE project tells us, geneticists have discovered several dozen mutations and variations in DNA associated with high academic performance at school and university or a high level of intelligence. Stefansson and his colleagues decided to test how these variations affect the probability of procreation, the number of children and other important parameters from the point of view of evolution.
To do this, scientists used deCODE's data banks, and compared the levels of education and small mutations in the DNA of about 110 thousand Icelanders – about a third of the total population of the island. Since the level of academic performance is influenced by dozens and hundreds of different genes, scientists studied not individual mutations and DNA fragments, but whole groups of genes.
In conducting such an analysis, scientists were greatly helped by the fact that Iceland is a fairly isolated island with a well-studied genealogy of the population and statistics on the academic performance of children, parents, grandparents, great-grandparents and their ancestors.
In total, as scientists' calculations show, all the genes associated with the level of intelligence and academic success determine about 3.7% of how well Icelanders cope with their studies. Individual genes were associated with intelligence even less – at best, this figure reached 0.1%. This is a relatively small indicator, but it is enough to determine whether there is a connection between the number of children, genes and education, or that there is not.
According to Stefannson, such dependence really exists, and it is negative – in other words, the more "smart" genes a person's genome contains, the fewer children he or she produces.
Interestingly, for some reasons that are not yet clear, this effect completely disappeared, if you do not take into account young people aged 22-23 years. On average, if we take into account the entire population of Iceland who participated in this study, carriers of "smart" genes produced 6% fewer children than other people.
If we translate this discovery into the language of biology, then we can say that being smart is not profitable in evolutionary terms – the children of smart parents will leave fewer offspring and die more often without children than other people. Accordingly, after a while, smart people should completely give way to competitors with an "average" level of development, more successful in terms of reproduction and attracting the opposite sex. This process, as scientists note, can be seen already today – the proportion of people with combinations of a large number of "smart" genes is not much, but has decreased compared to 1990.
Portal "Eternal youth" http://vechnayamolodost.ru 17.01.2017