Динамический адаптационный полиморфизм Fruticicola fruticum (müll.)

Abstract

Одна из элементарных окрасочных систем раковины наземных моллюсков – наличие или отсутствие на раковине цветных спиральных полос («опоясанность»). Этот признак у генетически изученных видов характеризует полиморфизм популяций.

Одна з елементарних колірних систем черепашки наземних молюсків – наявність або відсутність на черепашці кольорових спіральних смуг («поясків»). Ця ознака у генетично вивчених видів характеризує поліморфізм популяцій.

One of the elementary colouration systems of landsnail shells is the presence or absence of colourful spiral bands (“banding”). In genetically studied species this sign is characteristic of population polymorphism. Many-year studies of natural landsnail populations were carried out in 1968–2009 in various biotops of the PreUrals (1-the preKama forest near Sarapul, 2 – Bashkir steppe near Sterlitamak) and the TransUrals (the prePyshma forest, Sverdlovsk region, near Belsky settlement). The effects of climate and fluctuating weather conditions in various years on the ratios of single-band (aa) and bandless (AA and Aa) morphs were found to be different in geographically different habitats. The effects were stronger in extreme habitats. Balanced polymorphism was stable in natural populations; colour type frequencies might exist for a long time; stabilizing selection was observed. Thus, the genetic variability of populations was realized by spatial and temporal variabilities, it was closely connected with the environment heterogeneity. A polymorphic population was less specialized than a monomorphic one, its greater genetic variability allowed to effectively use the environmental resources. The polymorphic structure significantly increased the population adaptive abilities.