GENETIC DRIFT AND GENE FLOW IN POPULATIONS OF THE GREAT GERBILS

Abstract

The article describes the additional evolutionary factors, apart from natural selection, which can influence the genetic structure of the populations of the main carriers of the plague microbe – the great gerbil. The influence of genetic drift on random fluctuation of alleles is considered. With the help of a stochastic matrix, on the example of the family group of gerbils consisting of four individuals, the probabilities of the transition of allele frequencies from parents to offspring are calculated. Based on the previously calculated size of the neighborhood in gerbils, it is concluded that any large population of great gerbils can be considered as small in terms of deviation of gene frequencies. In such small groups – parcels – the drift of genes will be of great importance. In addition, the effect of the gene flow on the genetic structure of the gerbil population on the example of the simplest population model “continent-island” is considered. The dynamics of changes in allelic frequencies for 100 generations has been calculated. It is shown that the allele frequency during the 20-30 generations changes at the maximum rate, and then slows as the equilibrium is approached. It is concluded that different populations of gerbils should be considered as separate historically formed structures, with different sequence of influence of external environmental factors on them.

Keywords

• great gerbil
• population
• genetic drift
• gene flow