CAREER: Sperm Limitation, Sperm Competition, and Sexual Selection in Free Spawning Invertebrates

由于精子的数量远远超过卵子，进化生物学家长期以来一直认为精子竞争是推动性别差异进化的选择机制;男性受到交配机会的限制并为交配机会而竞争，而女性则不受配偶的限制并表现出配偶选择。 支持这些观点的证据来自内部受精或精子沉积在卵子上的物种。 然而，祖先的，仍然普遍的生殖策略是将卵子和精子释放到环境中，与内部受精相比，受精的机会大大减少。 在这些条件下，雄性和精子的低密度会限制雌性的繁殖成功。 该提案将调查精子和卵子性状如何影响实验室和海洋中的受精率，自然无脊椎动物种群中常见的精子限制和精子竞争以及配子竞争如何影响自由产卵海洋无脊椎动物性别差异的演变。 这项工作将涉及实验室和田间实验，有时使用分子技术来更好地了解交配系统的进化。

Because sperm greatly outnumber eggs, evolutionary biologists have long thought that sperm competition is the selective mechanism driving the evolution of gender differences; males are limited by and compete for mating opportunities, while females are not limited by mates and exhibit mate choice. The evidence supporting these ideas come from species with internal fertilization or in situation where sperm are deposited on eggs. However, the ancestral, and still widespread, reproductive strategy is to release eggs and sperm into the environment where the chance of fertilization is much reduced compared to internal fertilization. Under these conditions, low densities of males and sperm can limit female reproductive success. This proposal will investigate how sperm and egg traits influence fertilization rates in the laboratory and ocean, how common sperm limitation and sperm competition are in natural invertebrate populations and how gamete competition can influence the evolution of gender differences in free spawning marine invertebrates. The work will involve laboratory and field experiments, at times using molecular techniques to better understand the evolution of mating systems.