Evolution selects the uneducated, short and fat

Scientists have determined that education is one of the engines of modern human evolution

Anastasia Lebedeva, "Gazeta.Ru"

Geneticists have finally found out whether human evolution has stopped or is still continuing. The study showed that natural selection still affects the growth and development of the population. Department of Science "Newspapers.Ru" figured out what characteristics of the phenotype can be a consequence of the evolutionary process and how the level of education of people is related to their ability to reproduce.

Natural selection regulates the evolutionary process, during which the number of individuals in the population increases, maximally adapted to certain living conditions. Fitness, in turn, is determined by the genotype and habitat of the organism and manifests itself through the phenotype – a set of special features of a living organism formed during its individual development.

Anthropologists and biologists all over the world are wondering whether the evolution of Homo sapiens is taking place right now, and are also trying to find out what exactly in modern life can affect the fitness of people, that is, the ability of individuals with a certain genotype to reproduce.

Some scientists assumed that man stopped evolving about 40-50 thousand years ago, but it turned out that traits such as resistance to malaria and adaptation to altitude zones arose relatively recently. In addition, it turned out that the body mass index and height of Europeans are also the result of natural selection.

In previous studies, scientists have already tried to understand how lifelong reproductive success (the number of copies of genes that parents pass on to the next generation, also capable of reproduction) is related to various phenotypes of the modern human population, which is characterized by a fairly low mortality, and found that these two indicators correlate with each other.

Jonathan Beauchamp and a team of scientists from Harvard University used statistical methods to analyze the relationship between relative lifetime reproductive success – the ratio of a person's reproductive success rate to the average reproductive success rate of people of the same sex and age – and genetic variations associated with a particular phenotype. The analysis covers women and men whose phenotype was characterized by seven different indicators: BMI, height, fasting blood glucose, total plasma cholesterol, as well as the age at which the women participating in the study began their first menstruation (menarche). Geneticists also considered the level of education received, which, as it was proved earlier, partly depends on genetics, and a person's tendency to develop schizophrenia.

The researchers focused their attention on people of predominantly European descent who were born between 1931 and 1953 and participated in the American HRS Health Study. This study includes information about the health of 20 thousand people over 50 years old who, due to their age, are no longer able to continue childbirth.

It turned out that people with a low level of education, as well as women of low height or overweight have the highest relative lifetime reproductive success.

To check whether natural selection acts on genetic variations associated with these phenotypes, the scientists used the final statistical data to search for differences in the DNA sequence of one nucleotide (single nucleotide polymorphisms) in the genome of the studied people. Jonathan Beauchamp managed to find out that natural selection really gives an advantage to people with genes associated with a low level of education.

According to the results of a study published in the scientific journal PNAS (Beauchamp, Genetic evidence for natural selection in humans in the contemporary United States), scientists have suggested that since, in addition to the negative relationship between the level of relative lifelong reproductive success with the level of education of both sexes, the relationship between other indicators is not so great, their absence may be due to with a lack of statistical information.

Nevertheless, American researchers blame natural selection for the unwillingness of people with a good education to have many children. In addition to the fact that educated people have fewer children, this often happens in adulthood, which also reduces the chances of offspring for successful reproduction.

However, there is no need to be afraid that soon, as a result of natural selection, the genes that contribute to getting a good education will disappear altogether: it is also important that natural selection today acts more slowly than in the era when environmental factors largely regulated whether this or that individual would survive or not. Man has adapted to the harshest natural conditions, and this means that completely different processes are beginning to influence the course of evolution. In addition, the degree of education of a person depends not only on genetics, but also on the social conditions in which a person is brought up.

Portal "Eternal youth" http://vechnayamolodost.ru  12.07.2016