CAREER: Investigating Fitness Trade-offs In A Southern Ocean Predator, The Leopard Seal

雄性和雌性之间的特征差异在动物王国中普遍存在。由于这些特征往往会导致影响生殖成功和生存的权衡，因此理解它们是生物学中的一个基本问题。豹海豹是南大洋的大型食肉动物，也是哺乳动物中雌性偏向二态性的极端例子，雌性比雄性大。然而，这些尺寸差异的影响尚不清楚。该项目将调查豹海豹雌性偏态的原因和后果，并将产生关于这种重要而神秘的极地食肉动物的生活史、生殖生理学和繁殖生物学的新数据。这些信息对于了解豹海豹的过去、现在和未来至关重要——从物种如何进化到预测它们在前所未有的环境变化时代的适应能力。该项目也有很强的教育成分。它旨在通过培训、指导和支持两名博士后、两名研究生和25名以上的本科生，增加历史上被排除在极地生物学之外的群体的参与。它还将通过在地方、国家和国际范围内的推广活动，吸引学生和公众参与科学研究。从种内适应度的差异到物种水平的生活史策略，性状差异可以导致重要的权衡，影响多个尺度上的生物过程。豹海豹表现出一种极端的雌性体型二态性。然而，对于独居的，广泛分布的极地物种，如豹海豹，很难研究它们的生活史和生殖生物学。因此，尚不清楚豹海豹的体型二态性与它们生物学的其他方面有何关系。这个项目的目标是研究豹海豹中与雌性偏二态性相关的健康权衡。具体而言，本研究将(1)评估雄性和雌性形态和生活史的差异；(2)比较雄性和雌性的生殖生理；(3)研究它们的繁殖行为和生殖活动；(4)对哺乳动物雌性偏态二态现象进行跨枝合成。该小组将分析现有的生物标本，并开展实地工作，以产生新的、互补的数据。这些信息对于了解豹海豹是如何进化到在南大洋生存和生存的至关重要。这项研究与美国国家科学基金会的南极和南大洋研究投资战略愿景一致，并支持正在进行的努力，以创建和利用开放的极地研究软件，以及极地研究中的数据和样本重用。这项工作依赖于全球学术界、非营利组织和政府机构之间的强有力合作，其成果将与全球受众广泛分享。该项目还旨在增加历史上被排斥群体的人参与和保留极地研究。具体来说，目标是(1)招募和培养一个多元化、包容性和支持性的研究团队，(2)领导一个研究密集型的本科课程（海豹实验室），以及(3)为研究生和博士后提供实际的领导和指导经验。该项目将吸引学生和公众参与极地研究，因为学生将在博物馆、野外和实验室环境中进行研究。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Part 1: Non-technical summary Trait differences between males and females are widespread across the animal kingdom. Because these traits often lead to trade-offs that affect reproductive success and survival, understanding them is a fundamental question in biology. Leopard seals are large predators in the Southern Ocean and an extreme example of female-biased dimorphism in mammals, where females are the larger than males. Yet, the effects of these size differences are unknown. This project will investigate the causes and consequences of female-biased dimorphism in leopard seals and will generate new data on the life history, reproductive physiology, and breeding biology of this important and enigmatic polar predator. This information is critical for understanding leopard seals' past, present, and future—from how the species evolved to predicting their resilience in an era of unprecedented environmental change. The project also has a strong education component. It aims to increase the participation of people from historically excluded groups in polar biology by training, mentoring, and supporting two postdocs, two grad students, and 25+ undergraduates. It will also engage students and the public in scientific research through outreach activities at local, national, and international scales.Part 2: Technical summaryTrait differences can lead to important trade-offs that affect biological processes at multiple scales, from intraspecific differences in fitness to species-level life history strategies. Leopard seals exhibit an extreme form of female-biased size dimorphism. However, for solitary, wide-ranging polar species like leopard seals, it is difficult to study their life history and reproductive biology. As a result, it is unknown how leopard seals' size dimorphism relates to other aspects of their biology. The goal of this project is to examine fitness trade-offs associated with female-biased dimorphism in leopard seals. Specifically, this study will (1) assess differences in male and female morphology and life history, (2) compare reproductive physiology between males and females, (3) investigate their breeding behavior and reproductive activities, and (4) conduct a cross-clade synthesis of female-biased dimorphism in mammals. The team will analyze existing specimens from biological collections and conduct field efforts to generate novel, complementary data. This information is critical for understanding how leopard seals evolved to survive and persist in the Southern Ocean. The research aligns with NSF's Strategic Vision for Investments in Antarctic and Southern Ocean Research and supports ongoing efforts to create and utilize open polar research software, as well as data and sample reuse in polar research. This work relies on strong collaborations across academia, non-profits, and government institutions worldwide, and the results will be broadly shared with global audiences. This project also aims to increase the participation and retention of people from historically excluded groups in polar research. Specifically, the goals are to (1) recruit and train a diverse, inclusive, and supportive research team, (2) lead a research-intensive undergrad course (SEAL Lab), and (3) provide grad students and postdocs with hands-on leadership and mentoring experiences. The project will engage students and the public in polar research, as students will conduct research in museum, field, and lab-based settings.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.