The evolution of female mating systems: tracing the origins and tracking the consequences

进化生物学的一个关键焦点是了解交配模式如何在不同的物种和种群中进化。对交配行为的研究历来集中在为什么过度的男性特征会进化，但近年来发现了女性交配行为的更微妙的方面。传统上，女性被认为只交配一次(一夫多妻制)，以获得足够的精子来繁殖。然而，现在很明显，一夫多妻制很少见，女性通常会与多个男性交配(一夫多妻制)。最近的研究表明，虽然一夫多妻制可能代价高昂，但它也可以让雌性繁殖更多的后代，而且一夫多妻制的种群灭绝的可能性较小。然而，虽然我们知道女性偏好可以推动过度的男性特征(如孔雀尾巴)的进化变化，但我们仍然不知道是什么驱动了不同的女性交配率的进化，以及为什么一夫多妻制如此罕见。我建议的工作将促进我们对雌性交配策略的理解，拓宽领域，询问关于雌性交配系统如何变化以及为什么变化的问题。我将开发模拟模型(ColLab.(Brad Duthie博士)来推断生活在数十亿年前的第一次有性繁殖生物交配的次数。这些模型将帮助我理解古代生物的交配模式是如何随着有性繁殖而进化的，就不同性别(雄性和雌性)和内部受精(交配)的进化而言。然后，我将构建一个进化模型，以观察一种新物种--寄生蜂--雌性交配行为的更精细规模和更新的变化。寄生蜂是防治害虫的重要天敌，对其行为、生理、遗传等方面都有较深入的了解。特别是，寄生雌蜂在不同物种之间的交配率不同，从无性(无交配)到一夫多妻和一夫多妻。寄生蜂中雌性交配模式的多样性和知识将使我能够使用进化分析来估计雌性交配行为在过去发生变化的时间和原因，以及这些变化是否会驱动其他特征的进化(协作。Sally Street博士)。例如，寄生蜂在性别比例上表现出很大的变化；在某些物种中，90%以上的种群是雌性。我预测，一夫多妻制将在性别比例严重偏向女性的物种中更加常见，这样雌性就可以获得足够的精子来繁殖。我还将使用实验进化来实时跟踪雌性交配行为的变化，在棉铃虫寄生蜂Lysiphlebus Fabarum(ColLab.克里斯托夫·沃伯格教授)。我将在斯特林大学进行实验，建立由一夫多妻制和无性恋雌性组成的温室种群，然后改变性别比例，以限制或增加雄性的可获得性。我将测量几代人的雌性交配率，以测试交配限制等因素是否会导致不同雌性交配策略的频率发生变化。我的结果将揭示一夫多妻制、单性或无性寄生蜂可能对灭绝威胁(如气候变化)更强大。这些发现还对寄生蜂控制害虫和入侵物种具有重要意义，并可用于制定长期可持续和具有成本效益的生物防治战略，以控制作物害虫和入侵物种。我建立的国际伙伴关系(Luc Bussiere博士、Bart Pannebakker博士)将有助于将我的发现传播给行业利益相关者，以便将我的见解纳入政策。除了我的实验工作，我还将使用文献计量学技术来分析研究论文，并调查整合新方法和更多样化的性别视角如何塑造我们对雌性交配行为的理解。

A key focus in evolutionary biology has been to understand how mating patterns evolve in different species and populations. Research into mating behaviour has historically focussed on why extravagant male traits evolve, but in recent years more subtle aspects of female mating behaviour have been uncovered. Traditionally females were assumed to mate only once (monandry) to acquire enough sperm to reproduce. However, it is now clear that monandry is rare and that females typically mate with multiple males (polyandry). Recent work has shown that while polyandry can be costly, it can also allow females to produce more offspring, and that polyandrous populations can be less likely to go extinct. Yet, while we know that female preference can drive evolutionary change in extravagant male traits (like the peacock's tail), we still do not know what drives the evolution of different female mating rates and why monandry is so rare. The work that I propose will advance our understanding of female mating strategies, broadening the field to ask questions about how and why female mating systems change. I will develop simulation models (collab. Dr Brad Duthie) to infer how many times the first sexually reproducing organisms, which lived billions of years ago, mated. These models will help me to understand how mating patterns in ancient organisms evolved alongside sexual reproduction, in terms of the evolution of separate sexes (males and females) and internal fertilisation (mating). I will then construct an evolutionary model to look at finer scale and more recent changes in female mating behaviour in a novel group of species, the parasitoid wasps. Parasitoid wasps are important natural enemies that are used to control pest species, so we know a lot about their behaviour, physiology and genetics. In particular, parasitoid females have diverse mating rates across different species ranging from asexuality (no-mating) through to monandry and polyandry. The diversity in and knowledge of female mating patterns across the parasitoids will allow me to use evolutionary analyses to estimate when and why female mating behaviour changed in the past, and whether these changes drive the evolution of other traits (collab. Dr Sally Street). As an example, parasitoids show great variation in the sex ratio; in some species over 90% of the population are female. I predict that polyandry will be more common in species with strongly female-biased sex ratios, so that females can obtain enough sperm to reproduce.I will also track changes in female mating behaviour in real-time using experimental evolution in the aphid parasitoid Lysiphlebus fabarum (collab. Prof Christoph Vorburger). I will run experiments at the University of Stirling, setting up greenhouse populations comprised of monandrous, polyandrous and asexual females and then alter the sex ratio, to either limit or increase the availability of males. I will measure female mating rates over generations to test whether factors such as mate-limitation drive changes in the frequency of different female mating strategies.My results will reveal whether polyandrous, monandrous or asexual parasitoids are likely to be more robust to extinction threats (such as climate change). These findings also have important ramifications for the control of pests and invasive species by parasitoid wasps and could be used to develop long-term sustainable and cost-effective biological control strategies in order to control crop pests and invasive species. The international partnerships that I have developed (Dr Luc Bussiere, Dr Bart Pannebakker) will facilitate the dissemination of my findings to industrial stakeholders so that my insights can be integrated into policy. Alongside my experimental work, I will also use bibliometric techniques to analyse research papers and investigate how integrating new methods and more diverse gender perspectives has shaped our understanding of female mating behaviour.