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，生物体必须有策略地将资源分配给不同的功能。因此，对一种性状的高投入会导致对其他性状的低投入，并且最优分配策略会随着环境的变化而变化。大多数关于进化权衡的研究要么关注导致不同策略的机制，要么关注它们的适应性结果，而不是将这两个问题结合起来。该项目的目标是调查使用豆甲虫（Callosobruchus maculatus）进行权衡的原因和后果。研究者和两位本科生之前的一项研究表明，幼鸟之间的资源竞争导致了成年鸟在翅膀大小和繁殖之间的权衡。该项目将探讨发育过程中激素在决定成虫分配到翅膀和繁殖策略中的作用，以及资源分配对免疫的影响。这些权衡的结果也将通过测量具有不同行为策略的个体的进化适应性来研究。除了对我们对生活史权衡的理解做出重大贡献外，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者的监督下进行。此外，本计画将透过动物行为学课程中探究性实验的发展，促进教学与研究的整合。这种课堂研究经验将作为本科生参与课堂外研究的管道。权衡是生命史理论的核心概念，由于生物体内的差异性状投资而产生，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，就需要整合它们的近似机制和适应性结果。在斑纹卡洛索布鲁克斯（Callosobruchus maculatus）中，幼虫密度导致资源分配的差异：高密度导致具有大功能翅膀的分散型，而低密度下发育的短翼无飞型。研究者和两名本科合作者先前的一项研究表明，密度高的个体会发育出更大的翅膀和更小的性腺，而且幼虫密度也会影响两性的一系列交配行为。本项目将研究幼激素在这些权衡中所涉及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整体资源分配。最终的解释还将通过测量对性腺的不同分配和交配行为（如求偶和产卵策略）的适合度效应来研究。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。

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.