Data from: Bet hedging via multiple mating: a meta-analysis

Polyandry has been hypothesized to allow females to “bet hedge” against mating only with unsuitable mates, reducing variance in offspring fitness between members of a polyandrous lineage relative to a single-mating one. Theoretically, this reduction in fitness variance could select for polyandrous genotypes even when polyandry carries a direct cost, especially in small populations. However, this hypothesis is controversial and difficult to test empirically. Here, I apply a novel simulation model to 49 published empirical datasets, and quantify the potential selective advantage of multiple mating via reduced offspring fitness variance. For a wide range of assumptions, including those that most favor the evolution of bet hedging, I show that any fitness gains are meager. The variance in offspring quality caused by mate identity does not appear to be high enough for bet hedging to drive the evolution of polyandry.

学界曾提出假说，认为一妻多夫制（polyandry）可使雌性通过“避险策略（bet hedging）”规避仅与不适配偶交配的风险，相较于单配偶交配谱系，一妻多夫谱系内个体间的后代适合度方差更低。从理论层面而言，即便一妻多夫制会产生直接适应性成本，这种适合度方差的降低仍可能对一妻多夫型基因型产生正向选择，尤其在小型种群中更为显著。然而，该假说尚存争议，且难以通过实证研究加以验证。本研究将全新开发的模拟模型应用于49份已发表的实证数据集，通过后代适合度方差降低的效应，量化了多配偶交配的潜在选择优势。在涵盖最有利于避险策略演化的各类假设场景中，本研究显示相关适合度收益均极为微薄。由配偶身份差异引发的后代质量方差，似乎并未达到足以让避险策略推动一妻多夫制演化的临界水平。