Tanaka Mark M, Bonduriansky Russell
School of Biotechnology and Biomolecular Sciences UNSW, Sydney, Australia.
Evolution and Ecology Research Centre, UNSW, Sydney, Australia.
Evolution. 2025 Oct 17;79(10):2250-2258. doi: 10.1093/evolut/qpaf155.
Facultative parthenogenesis is a flexible reproductive strategy in which females can reproduce asexually if males are unavailable. When males are present, females can incorporate potentially beneficial genes from males into their offspring genomes; when males are absent, females can still produce offspring and benefit from the twofold advantage of parthenogenesis. Given these advantages, it is puzzling that this reproductive strategy is not more widespread. While a number of selection-based explanations have been proposed, fundamental questions remain about the role of population ecology in the evolution of facultative parthenogenesis. Here, we consider the roles of dispersal and genetic drift in the evolution of facultative parthenogenesis within a sexually reproducing species. We develop and analyze a simple mathematical model with two parameters: the dispersal intensity and the population size. We find that a combination of drift and dispersal forms a barrier to the invasion of obligately sexual populations by facultatively parthenogenetic mutants. Although these factors are unlikely to be the only forces that limit facultative parthenogenesis, they represent a parsimonious null model for the observed relative rarity of this reproductive strategy in some taxonomic groups.
兼性孤雌生殖是一种灵活的生殖策略，在这种策略中，如果没有雄性，雌性可以进行无性繁殖。当有雄性存在时，雌性可以将来自雄性的潜在有益基因纳入其后代基因组；当没有雄性时，雌性仍然可以产生后代，并从孤雌生殖的双重优势中受益。鉴于这些优势，令人困惑的是这种生殖策略并没有更广泛地存在。虽然已经提出了一些基于选择的解释，但关于种群生态学在兼性孤雌生殖进化中的作用仍然存在基本问题。在这里，我们考虑扩散和遗传漂变在有性生殖物种内兼性孤雌生殖进化中的作用。我们开发并分析了一个具有两个参数的简单数学模型：扩散强度和种群大小。我们发现，漂变和扩散的结合形成了一个障碍，阻止兼性孤雌生殖突变体侵入 obligately sexual populations（这里原文有误，推测是obligately sexual populations，即完全有性生殖种群）。虽然这些因素不太可能是限制兼性孤雌生殖的唯一力量，但它们代表了一个简约的零模型，用于解释在某些分类群中观察到的这种生殖策略相对罕见的现象。
