Groningen Institute for Evolutionary Life Sciences, Faculty of Science and Engineering, University of Groningen, Groningen, The Netherlands.
Centre for Ecology, Evolution and Conservation, School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, UK.
Evolution. 2022 May;76(5):915-930. doi: 10.1111/evo.14473. Epub 2022 Apr 9.
In socially monogamous species, extra-pair paternity (EPP) is predicted to increase variance in male reproductive success (RS) beyond that resulting from genetic monogamy, thus, increasing the "opportunity for selection" (maximum strength of selection that can act on traits). This prediction is challenging to investigate in wild populations because lifetime reproduction data are often incomplete. Moreover, age-specific variances in reproduction have been rarely quantified. We analyzed 21 years of near-complete social and genetic reproduction data from an insular population of Seychelles warblers (Acrocephalus sechellensis). We quantified EPP's contribution to lifetime and age-specific opportunities for selection in males. We compared the variance in male genetic RS vs social ("apparent") RS (RS ) to assess if EPP increased the opportunity for selection over that resulting from genetic monogamy. Despite not causing a statistically significant excess (19%) of the former over the latter, EPP contributed substantially (27%) to the variance in lifetime RS, similarly to within-pair paternity (WPP, 39%) and to the positive WPP-EPP covariance (34%). Partitioning the opportunity for selection into age-specific (co)variance components, showed that EPP also provided a substantial contribution at most ages, varying with age. Therefore, despite possibly not playing the main role in shaping sexual selection in Seychelles warblers, EPP provided a substantial contribution to the lifetime and age-specific opportunity for selection, which can influence evolutionary processes in age-structured populations.
在社会一夫一妻制的物种中，预测额外配对父权（EPP）会增加雄性生殖成功（RS）的方差，超出遗传一夫一妻制的影响，从而增加“选择机会”（可以作用于特征的最大选择强度）。由于终身繁殖数据通常不完整，因此，在野外种群中研究这一预测具有挑战性。此外，繁殖的年龄特异性方差很少被量化。我们分析了来自塞舌尔莺（Acrocephalus sechellensis）一个岛屿种群的 21 年近乎完整的社会和遗传繁殖数据。我们量化了 EPP 对雄性终生和年龄特异性选择机会的贡献。我们比较了雄性遗传 RS 与社会（“表观”）RS（RS）的方差，以评估 EPP 是否增加了选择机会，超过了遗传一夫一妻制的影响。尽管 EPP 没有导致前者相对于后者的统计上显著过剩（19%），但它对终生 RS 的方差贡献很大（27%），与配对内父权（WPP，39%）和正 WPP-EPP 协方差（34%）相似。将选择机会划分为年龄特异性（共）方差分量，表明 EPP 在大多数年龄段也提供了大量贡献，随年龄而变化。因此，尽管 EPP 可能在塑造塞舌尔莺的性选择中不起主要作用，但它对终生和年龄特异性选择机会提供了大量贡献，这可以影响年龄结构种群中的进化过程。
