Genetic and Morphological Variability and Diff erentiation of Mussels (Bivavia, Unionidae, Anodontinae) in Ukraine. Mezhzherin S. V., Yanovich L. M., Zhalay Е. I., Vasilieva L. А., Pampura М. М. - Th e study of allozymes variation and sequence analysis of two mitochondrial genes supports the concept that there are four species of subfamily Anodontinae in the Eastern European fauna, three of them; Anodonta cygnea Linnaeus, 1758; A. anatina Linnaeus, 1758; Pseudanodonta complanata (Rossmassler, 1835) are indigenous and one is invasive (Sinanodonta woodiana Lea, 1834). Th is paper analyzes morphological diagnostic features of which some can be used in identification of these species.
Geographical parthenogenesis describes phenomenon when parthenogenetic hybrid forms or species have larger distribution areas or higher abundance than their amphimictic parental species, especially in climatically unfavorable conditions. This phenomenon was studied in Ukraine for the pair species of earthworms Aporrectodea сaliginosa (Savigny, 1826) s. l. We found that the hermaphroditic amphimictic A. caliginosa clearly predominates in the northern and western regions, and the apomictic parthenogenetic A. trapezoides (Duges, 1828) in the southern and eastern regions with a continental arid climate. In the sample sets of A. сaliginosa–A. trapezoides group, usually one of the species sharply predominated, and the equality of their abundance was very rare. The reason for this fact is both the alternative geographical distribution and the ability of A. trapezoides to form populations in habitats unfavorable for A. caliginosa. In general, the situation in this group agrees with the classical model of geographic parthenogenesis and confirms the high adaptive potential of apomictic organisms. This fact once again raises the question of non-adaptive reasons for the exclusion of the apomictic reproduction in highly organized animals.
Вопрос об эволюционном значении клонового способа размножения и партеногенеза, как одной из форм, крайне актуальный в современной биологии [1, 2]. Клонирование является эволюционно первичным способом репродукции, свойственным всем без исключения одноклеточным и примитивным многоклеточным. Преимущества этого способа размножения очевидны-потомству строго передаются наиболее удачные сочетания генов. Неслучайно самый большой период жизни на Земле занимает время доминирования бесполого размножения, тогда же и имели место ключевые ароморфозы. Тем не менее в процессе эволюции у многоклеточных организмов все большую роль стал играть амфимиксис, а у высокоорганизованных животных апомиксис становится крайне редким и, по сути, исключительным способом воспроизводства. Партеногенез, как природное явление, описан у многих достаточно высокоорганизованных животных [3]. Большей частью это обитатели пресных вод и суши. Как ни парадоксально, виды, отказавшиеся от амфимиксиса, ока
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