Centre for Evolutionary Biology, School of Biological Sciences, University of Western Australia.
Philos Trans R Soc Lond B Biol Sci. 2020 Dec 7;375(1813):20200069. doi: 10.1098/rstb.2020.0069. Epub 2020 Oct 19.
Broadcast spawning invertebrates offer highly tractable models for evaluating sperm competition, gamete-level mate choice and sexual conflict. By displaying the ancestral mating strategy of external fertilization, where sexual selection is constrained to act after gamete release, broadcast spawners also offer potential evolutionary insights into the cascade of events that led to sexual reproduction in more 'derived' groups (including humans). Moreover, the dynamic reproductive conditions faced by these animals mean that the strength and direction of sexual selection on both males and females can vary considerably. These attributes make broadcast spawning invertebrate systems uniquely suited to testing, extending, and sometimes challenging classic and contemporary ideas in sperm competition, many of which were first captured in Parker's seminal papers on the topic. Here, we provide a synthesis outlining progress in these fields, and highlight the burgeoning potential for broadcast spawners to provide both evolutionary and mechanistic understanding into gamete-level sexual selection more broadly across the animal kingdom. This article is part of the theme issue 'Fifty years of sperm competition'.
广播式产卵无脊椎动物为评估精子竞争、配子水平的配偶选择和性冲突提供了高度可行的模型。通过展示祖先的体外受精交配策略，即性选择只能在配子释放后发挥作用，广播式产卵动物也为更“衍生”的群体（包括人类）中导致有性繁殖的一系列事件提供了潜在的进化见解。此外，这些动物面临的动态繁殖条件意味着雄性和雌性的性选择强度和方向都可能有很大差异。这些特征使广播式产卵无脊椎动物系统非常适合测试、扩展，有时甚至挑战精子竞争中的经典和当代观点，其中许多观点最早是在 Parker 关于该主题的开创性论文中提出的。在这里，我们提供了一个综合概述，阐述了这些领域的进展，并强调了广播式产卵动物在更广泛的动物王国中提供配子水平性选择的进化和机制理解方面的新兴潜力。本文是主题为“精子竞争 50 年”的特刊的一部分。
