MOSCOW, May 11. /TASS/. An international research team including Russian researchers from the Skolkovo Institute of Science and Technology (Skoltech), Kharkevich Institute for Information Transmission Problems RAS, and the Moscow State University have determined how natural selection sifts out the population from mutations.
The researchers have clarified that the species with the larger number of changes bear fewer offspring and in that way are removed quite quickly from the population. The results of the study have been published in the journal Science.
In cells of human and other living creatures, mutations, the accidental changes in the DNA sequence, are constantly surfacing. Part of them lower the probability of producing offspring and such mutations are called deleterious. Over the course of time, natural selection removes such mutations from the population but until recently, biologists did not understand the mechanism of this process.
In the new study, researchers have tried to figure out the flow of natural selection. To do so, the genome of a human and a fruit fly drosophila (Drosophila melanogaster) have been analyzed. It turns out that the more deleterious mutations in the genome that are present, the more harmful any next subsequent mutation appears to be. Such correlations lead to the fact that the species with the largest number of deleterious mutations have only a few offspring.
Due to the fact that the carriers of a large number of deleterious mutation have notably lower probability to leave offspring, such genetic changes are removed from the population more effectively than one could expect without taking into account, the mutations interaction.
The obtained results are very instructive in understanding how the populations of living creatures including humans, can withstand the accumulation of deleterious genetic changes appearing in the genome in every generation.
The study was carried out in the framework of collaboration with researchers from the Harvard Medical School, the University of Michigan, and scientists from Netherlands.