Observation of the lives of Icelanders and the analysis of their DNA has helped scientists to prove the popular idea that the propensity to learn and a high level of intelligence adversely affect the prospects of procreation.
In recent years, scientists are actively trying to find genes and mutations associated with the development of autism, schizophrenia and other problems with brain function, as well as variations in the genes that are associated with abnormally high or low intellectual abilities. Like typos in the DNA, scientists find, by comparing the structure of genes in hundreds of thousands and even millions of people.
Recently, as told by Kari stefánsson (Kari Stefansson) project of deCODE genetics was opened a few tens of mutations and variations in DNA associated with high school and University or high level of intelligence. Stefansson and his colleagues decided to test how these variations affect the probability of reproduction, number of children and other important from the point of view of evolution parameters.
To do this, scientists have used data banks of the company deCODE, and compared between levels of education and small mutations in the DNA of the approximately 110 thousand Icelanders – about a third of the total population of the island. As the level of achievement is influenced by tens or hundreds of different genes, the scientists studied not individual mutations and DNA fragments, and whole groups of genes.
In conducting such analysis scientists much helped that Iceland is a fairly isolated island with well researched genealogy of the population and statistics on the performance of children, parents, grandparents, great-grandmothers and great grandfathers and their ancestors.
In sum, according to calculations of scientists, all genes related to IQ and success in school, determine approximately 3.7% on how well the Icelanders cope with their studies. Individual genes were associated with intelligence – even less so in the best case, this indicator reached 0.1%. This is a relatively small figure, but it is enough, in order to determine whether there is a relationship between the number of children, genes and education, or that it is not.
It tells Stefannson, such a relationship does exist, and it is negative – in other words, the more intelligent genes contain the genome of a person, the fewer children he or she to produce light.
Interestingly, for some not yet understood reasons, this effect completely disappeared, if not to take into account the young people at the age of 22-23 years. On average, if we consider the entire population of Iceland, participated in this study, carriers of the smart genes produced 6% fewer children than other people.
If we translate this discovery into the language of biology, we can say that to be smart is disadvantageous in evolutionary terms – the children of smart parents will leave fewer progeny and often die without children, than other people. Accordingly, after some time, intelligent people should give way to competitors with a medium level of development are more successful in terms of reproduction and attraction of the opposite sex. This process, as the researchers note, can be seen today — the proportion of people with kombinatsiyami a large number of intelligent genes only slightly, but decreased in comparison with 1990.