Boreskov

OP‐16modeled by the varying of inflow concentrations of NS. Stable trend of genome reductionwas shown to be major in both subcomfortable and comfortable conditions. The mostprimitive populations had only two genes for utilization: one for NS, another for SS. Theydisplaced all other populations. In subcomfortable conditions this led to the death of theprimitive one by reason of SS depletion. In comfortable conditions SS concentrationsupported by inflow and the primitive stayed alive.After that we have studied the influence of a phage infection on possible evolutionarytrends in communities of unicellulars. Addition of temperate phages into community led toinfection of all populations. A fraction of infected cells depended on both phages and cellsconcentrations in environment. The development of infected population was determined byconditions the “parent” population was in the moment of its infection. If it steadily grew, allinfected cells lysed with the formation of novel portion of phages. Contrariwise, if parentpopulation was in pessimal conditions and steadily depopulated, infected cells (all or a partof) switched to lysogenic cycle and became phage carriers, immune to infection by thatparticular phages. As a result, infection significantly changed evolutionary dynamics ofcommunity. It suppressed or even destroyed well‐growing populations and consequentlymaintained less competitive ones. On a series of computational experiments it has beenshown that in pessimal environmental conditions the populations which are far frommetabolic richness can survive and become leaders. It contrasts with the trend of genomeamplification mentioned above. Possible change of evolutionary trends caused by phageinfection was also found in cases of communities living in optimal environmental conditions.Computational modeling results have a stochastical character. In some experimentsinfection killed community. In other cases community perished before infection due to rapidgrowth of primitive populations. However the change of evolutionary trend occurred notalways.Therefore, our results show that the infection process of unicellulars’ community bytemperate phages has a capability to change evolutionary trend of community.[1]. S.A. Lashin, V.V. Suslov and Yu.G. Matushkin. Comparative Modeling Of Coevolution In Communities OfUnicellular Organisms: Adaptability And Biodiversity. Journal of Bioinformatics and Computational Biology,Vol. 8, No. 3 (2010) 627–643.57