Sexual selection under social constraints

性选择是一种强大的进化力量，在动物中产生了许多引人注目的特征，包括专门的武器，色彩鲜艳的装饰品和精心制作的求偶表演。它也是大量国际研究活动的焦点。因此，我们现在对潜在过程有了很好的机械理解（例如，配偶选择，性内竞争）。然而，这些过程中的每一个对繁殖成功和性选择特征进化的重要性仍然不清楚。原因之一是，尽管有越来越多的证据表明这些过程可以相互作用，但它们往往是独立研究的。第二个原因是，在群居动物中，研究忽视了社会因素的重要性。例如，在择偶研究中，雌性通常会被单独测试，这样她们就可以各自与自己喜欢的雄性交配。这种方法受到了批评，因为它模拟了一种罕见的情况--只有少数占主导地位的雌性经历过。在自然的社会条件下，大多数群居动物都是从属的。我将通过实验控制配偶选择、性内竞争和社会支配的表达，以揭示它们如何在复杂的社会系统中相互作用，从而塑造生殖成功和第二性征。研究将集中在黑顶山雀，这是一个理想的鸟类系统，其特点是稳定的群体结构和线性优势等级在两性。实验将揭示显性对第二性征的因果影响，配偶选择和两性间性内竞争的重要性，交配后精子竞争的作用，以及配对外交配的行为机制。我将分析整个群体，不仅考虑能够行使其理想选择的主导个体，还考虑选择受到限制的下属。性选择是一个热门话题，继续吸引国际研究界的关注;因此，我的研究结果将使加拿大的一个引人注目的研究领域作出独特的贡献。我的研究计划还将提供一个激励的环境，在其中培养下一代加拿大科学家。参与者将获得宝贵的经验，与鸟类和实地研究，与尖端技术量化第二性征（例如，声学分析、分光光度法、精子质量分析），以及用于定量激素和遗传亲子关系的实验室程序。结果将通过领先的国际期刊、会议报告、科学纪录片和大众媒体进行传播。这将最大限度地发挥我的研究的影响力，以及我吸引年轻人从事科学事业的能力。

Sexual selection is a powerful evolutionary force that has generated many spectacular traits among animals, including specialized weapons, brightly coloured ornaments, and elaborate courtship displays. It has also been the focus of tremendous international research activity. As a result, we now have an excellent mechanistic understanding of the underlying processes (e.g., mate choice, intrasexual competition). Yet, the importance of each of these processes to reproductive success and the evolution of sexually selected traits has remained unclear. One reason is that the processes are often studied independently, despite accumulating evidence that they can interact. A second reason is that, among group-living animals, studies have neglected the significance of social factors. In mate choice studies, for example, females are typically tested individually, such that they can each mate with their preferred male. This approach has been criticized because it simulates a rare condition - one that only the minority of dominant females ever experience. Under natural social conditions, the majority of group-living animals are subordinate.***I will experimentally control the expression of mate choice, intrasexual competition, and social dominance to reveal how they interact to shape reproductive success and secondary sexual characteristics in a complex social system. Studies will focus on the black-capped chickadee, which is an ideal avian system characterized by stable group structure and linear dominance hierarchies in both sexes. Experiments will reveal the causal effects of dominance on secondary sexual characteristics, the importance of mate choice and intrasexual competition in both sexes, the role of post-copulatory sperm competition, and the behavioural mechanisms underlying extrapair copulations. I will analyze the whole population, considering not just dominant individuals able to exercise their ideal choice, but also subordinates whose choices are constrained.***Sexual selection is a hot topic that continues to attract the attention of an international research community; my findings will hence make a distinctive Canadian contribution to a high-profile research area. My research program will also provide a stimulating environment in which to train the next generation of Canadian scientists. Participants will gain valuable experience with aviary and field-based research, with cutting-edge techniques for quantifying secondary sexual characteristics (e.g., acoustic analysis, spectrophotometry, analysis of sperm quality), and with laboratory procedures used in quantifying hormones and genetic parentage. Results will be communicated through leading international journals, conference presentations, science documentaries, and the popular press. This will maximize the impact of my research, as well as my ability to attract young people to careers in science.**