Abstracts

Evolution of Species and Ecosystems: Theoretical Analysis and Computer-Assisted Modeling

The computer models of population dynamics of the patterns of polygenic system of the additive quantitative trait, TEs and the labels of identity by origin (LIOs) under different variants of selection – directed (+)- and (-)-selection, (1) and (2) respectively, stabilizing (3) and disruptive (4), - were investigated. Under (1) and (2) there was fast and almost complete homozygotization of the polygenes and TE-modifiers up to 50^th generation. The behavior of TE-markers was similar with polygenes: under (+)-selection 73% loci and under (-)-selection 18% were fixed, and in sum total all these loci were homozygotizised very fastly. The most part of independent TE copies were also homozygotizised- ~89% and ~77% under (1) and (2), correspondingly, but proportion of fixations and losses were the same as their frequencies in initial generation. (3) Under selection for intermediate value of trait (stabilizing selection) population during long time was polymorphic: it contains monomorphic in average ~42% of polygenes and ~21% of TE-modifiers in 50^th generation; and approximately in 300^th generation the portion of homozygotizised polygenes and TE-modifiers reached 95%. The polygenes, not enforced by TE-modifiers, maintained their heterozygosity for very long time: ~50% in 500^th generation. The stabilizing selection did not lead to establishment of common pattern-consensuses: the polygenes with small contribution to the trait being not able to change the phenotype and fitness of individuals continued to be polymorphic. (4) Under the disruptive selection population was divided to two groups – one with large and another with small values of trait. They were homogeneous within themselves, - the observed internal heterozygosity was ~0,04, but were very distant between groups – 100% of difference by patterns of LIO in 50^th generation. The patterns of TEs and polygenes had, correspondingly, 52% и 73% differences. Such picture was conserved for many generations. The LIO pattern-consensus in 100^th generation was almost completely formed under (1), was not formed under (2) and (3), and was almost completely formed under (4), but contained two distant patterns-consensuses with the frequencies ~ 0.5. The inbreeding coefficient under (1) and (4) increased quickly to value ~ 1 up to 30-40-th generation, and slowly to the values ~ 0.9 и 0.7 to the 100^th generation under (2) and (3)

This work was supported by the grants of RFBR (№№ 97-04-49232, 00-04-49499) and of the program "Russian Universities – Basic Researches" (№ 1760) of the Russian Federation Ministry of Education.

Note. Abstracts are published in author's edition

|Home Page| |English Part|

Go to Home