RUI - An integrative study of covariances between behavioral and morphological life-history traits

权衡是进化生物学中的一个关键概念：当资源有限时，生物体必须战略性地将资源分配给不同的功能。因此，对一个性状的较高投资会导致对其他性状的较低投资，而最优配置策略可能会因环境而异。大多数关于进化权衡的研究要么集中在导致不同策略的机制上，要么集中在它们的适应性结果上，而不是将这两个问题结合起来。这个项目的目标是调查使用豆甲的权衡的原因和后果。研究人员和两名本科生研究人员之前的一项研究显示，幼鸟之间的资源竞争导致成年鸟的翅膀大小和繁殖力之间的权衡。这个项目将探索在发育过程中荷尔蒙在决定成虫翅膀与生殖的分配策略中的作用，以及资源分配对免疫的影响。这些权衡的后果也将通过衡量具有不同行为策略的个人的进化适合度来调查。除了对我们理解生命历史权衡做出重大贡献外，该项目还将通过招募和培训来自代表性不足群体的本科生研究人员，为更多样化的STEM劳动力做出贡献：该项目将完全由本科生研究人员在研究人员的监督下进行。此外，该项目还将通过为动物行为学课程开发基于探究的实验室实验，促进教学和研究的一体化。这一课堂研究经验将成为本科生参与课堂外研究的渠道。权衡是生活史理论的一个核心概念，它是由于生物体内不同的性状投资而产生的，并导致性状之间的负协方差。要充分理解为什么会发生权衡，就需要整合它们的直接机制和适应后果。在斑纹豆象中，幼虫密度导致不同的资源分配：高密度导致具有大而有功能的翅膀的分散型的发育，而不是在低密度下发育的短翅不能飞的型。研究人员和两名本科生合作者之前的一项研究显示，高密度个体发育出更大的翅膀和更小的性腺，幼虫密度也影响到两性的一系列交配行为。该项目将调查幼年激素在涉及这些权衡的发育机制中的作用，以及性别差异和免疫资源分配如何影响总体资源分配。最终的解释也将通过测量性腺不同分配和交配行为(如求偶和产卵策略)的健康影响进行调查。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Trade-offs are a key concept in evolutionary biology: when resources are limited, organisms must strategically allocate resources to different functions. As a result, higher investment in one trait results in lower investment in others, and the optimal allocation strategy can vary with the environment. Most studies on evolutionary trade-offs focus either on the mechanisms that result in different strategies or in their fitness consequences, rather than integrating these two questions. The goal of this project is to investigate both causes and consequences of trade-offs using the bean beetle, Callosobruchus maculatus. A previous study by the investigator and two undergraduate researchers revealed that resource competition between juveniles leads to trade-offs between wing size and reproduction in adults. This project will explore the role of hormones during development in determining adult allocation strategies into wings versus reproduction, as well as the effects of resource allocation to immunity. Consequences of these trade-offs will also be investigated by measuring the evolutionary fitness of individuals with different behavioral strategies. In addition to making significant contributions to our understanding of life-history trade-offs, this project will contribute to a more diverse STEM workforce through the recruitment and training of undergraduate researchers from underrepresented groups: This project will be entirely conducted by undergraduate researchers under the investigator’s supervision. Additionally, this project will promote the integration of teaching and research through the development of inquiry-based laboratory experiments with C. maculatus for an Animal Behavior course. This classroom research experience will serve as a pipeline for undergraduates to get involved in research outside the classroom. Trade-offs are a central concept to life-history theory, arising due to differential trait investment within an organism and resulting in negative covariances between traits. A full understanding of why trade-offs occur requires the integration of their proximate mechanisms and fitness consequences. In Callosobruchus maculatus, larval density induces differential resource allocation: High density results in the development of dispersal morphs with large, functional wings, as opposed to the short-winged flightless morphs that develop under low densities. A previous study by the investigator and two undergraduate collaborators revealed that high-density individuals develop larger wings and smaller gonads, and larval density also affected a suite of mating behaviors in both sexes. This project will investigate the role of Juvenile Hormone in the developmental mechanisms involved in these trade-offs, as well as how sex differences and resource allocation to immunity affect overall resource allocation. The ultimate explanations will also be investigated by measuring fitness effects of differential allocation to gonads and mating behaviors such as courtship and oviposition strategies.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.