Genetic monotony
The most genetically degenerate people is named
An international group of geneticists from the University of Copenhagen and the University of California found that a greater number of harmful mutations are common among Greenlandic Inuit than in other human populations. The reason is a small number of representatives of this ethnic group. Preprint of the paper by Pedersen et al. Extreme distribution of deleterious variation in a historically small and isolated population-insights from the Greenlandic Inuit is published on the bioRxiv website.
Scientists analyzed the genomes of 18 Inuit, deciphering DNA sequences encoding proteins. It turned out that the Greenland Eskimos over the past 20 thousand years have undergone the consequences of the bottleneck effect, when due to a critical decrease in the population, there is a reduction in genetic diversity - the gene pool. This led to a noticeable increase in the proportion of harmful mutations.
Biologists have found many signs indicating the genetic "degeneration" of the Inuit. Firstly, it is an increase in the average frequency of the allele in the population, a reduced frequency of heterozygosity and an increased frequency of monozygosity. With monozygosity, there is a high risk of hereditary diseases, since there are two identical copies of the gene in the cells of the body, which may be mutant.
Scientists believe that the Inuit population is an ideal object for studying the effects of gene drift. In addition, it is possible to study the spread of hereditary diseases that are rare in large populations.
Gene drift is understood as a change in the frequencies of allelic variants of genes in a population whose size has greatly decreased.
Alleles are forms of the same gene that are located on the same sections of the paternal and maternal chromosomes. If the alleles are the same, then the organism is called homozygous for this gene, if different, then heterozygous.
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04.07.2016