Sperm Economy between Female Mating Frequency and Male Ejaculate Allocation
Sperm Economy between Female Mating Frequency and Male Ejaculate Allocation
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DOI：
10.1086/679586
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发表时间：
2015-03-01
影响因子：
2.9
通讯作者：
Kamimura, Yoshitaka
中科院分区：
文献类型：
--
作者：
Abe, Jun;Kamimura, Yoshitaka
为什么许多物种的雌性会交配繁殖是进化生物学中的一个主要问题。此外，如果雌性多次接受交配，不同雄性的射精就会竞争受精（精子竞争），这使雄性面临如何为每次交配事件分配生殖资源的决定。尽管大多数现有模型都在假设异性策略水平固定的情况下研究了女性交配频率或男性射精分配，但这些策略可能会共同进化。为了研究群体中精子限制水平如何影响两性策略的相互作用，我们开发了模型，其中雌性调整其允许的交配次数，雄性在每次交配中分配射精量。我们的模型预测，由于雌性抵抗力和种群中精子的限制，雌性在性别比例均匀或极度偏向雌性的情况下仅交配一次或少于一次。然而，在适度偏向女性的情况下，雄性倾向于将生殖预算分配给许多雌性，而雌性则倾向于多次交配以获得足够的精子，这与大多数现有模型的预测相矛盾。我们讨论我们的模型的预测以及与现有模型的关系，并演示实证结果的应用。
Why females of many species mate multiply is a major question in evolutionary biology. Furthermore, if females accept matings more than once, ejaculates from different males compete for fertilization (sperm competition), which confronts males with the decision of how to allocate their reproductive resources to each mating event. Although most existing models have examined either female mating frequency or male ejaculate allocation while assuming fixed levels of the opposite sex's strategies, these strategies are likely to coevolve. To investigate how the interaction of the two sexes' strategies is influenced by the level of sperm limitation in the population, we developed models in which females adjust their number of allowable matings and males allocate their ejaculate in each mating. Our model predicts that females mate only once or less than once at an even sex ratio or in an extremely female-biased condition, because of female resistance and sperm limitation in the population, respectively. However, in a moderately female-biased condition, males favor partitioning their reproductive budgets across many females, whereas females favor multiple matings to obtain sufficient sperm, which contradicts the predictions of most existing models. We discuss our model's predictions and relationships with the existing models and demonstrate applications for empirical findings.