Collaborative Research: The Evolutionary Interplay between Life Histories, Morphologies, Performance, and Behavior in Trinidad Guppies

自然选择的进化，或适应的原则，是查尔斯达尔文提出的进化机制。达尔文认为，适应是生物体的任何特征，这些特征是自然选择的结果，并增强了个体的生存和繁殖潜力。然而，理解和经验记录之间的关系，似乎是适应性的一个特定的性状和选择的性状的进化的因素仍然是一个具有挑战性和争议性的任务。 自达尔文以来，从自然选择的实证研究中得到的主要教训是，适应很少孤立地发生，而是受到其他相互作用的特征的功能的限制，最终是有机体综合方面之间的妥协。 因此，适应性研究需要了解不同性状如何相互制约，以及它们如何整合以产生适应当地的表型。只有有限的经验证据表明，这种限制是如何表现在真实的生物体。拟议的工作将研究如何选择行为的整合生殖策略，身体形状，游泳的性能，和行为的孔雀鱼，孔雀鱼的自然种群。 孔雀鱼是拟议工作的模式生物，因为它是少数几个有适应记录的生物之一。 这项先前的工作表明，孔雀鱼的生殖特征在对掠食性鱼类的反应中发生了快速的适应性变化。 这里提出的工作将首先记录繁殖性状，身体形态，栖息地利用，觅食行为，和流类型与现场观察女性和男性孔雀鱼的人口受到不同的选择压力之间的相关性。它将集中在流电流和捕食的综合影响。由于孔雀鱼的生殖特征已经知道从这些网站，形态和行为的结果将提供第一个数据，无论是身体形态，觅食行为，栖息地的使用，和生殖策略可预见的相互协变，或者他们是否独立地变化，以应对不同的选择压力。然后，孔雀鱼将在实验室中在不同的环境下饲养，以测试种群之间的这些性状差异在多大程度上代表了固定的遗传差异或表型可塑性。最后，拟议的工作将首次研究怀孕对水生物种的身体形态和运动的影响，通过测量身体轮廓和游泳性能在生殖周期过程中的变化。稳定和逃避游泳性能的怀孕女性从高和低捕食的地方将测试不同的生殖分配运动的后果，以及如何适应后代数量的变化可能会损害运动。 通过研究生殖策略，形态，运动性能和行为如何相互作用，并共同应对不同的选择压力，拟议的工作将提供一个更好的了解所面临的权衡活轴承鱼适应当地环境。

Evolution by natural selection, or the principle of adaptation, was Charles Darwin's proposed mechanism for evolution. Darwin viewed an adaptation as any feature of an organism that arose as consequence of natural selection and enhanced the survival and reproductive potential of the individual. Yet, understanding and empirically documenting the relationship between a particular trait that appears to be adaptive and the factors that selected for the evolution of the trait remains a challenging and controversial task. In the time since Darwin, the main lessons learned from empirical studies of natural selection are that adaptations rarely occur in isolation, but rather are constrained by the function of other interacting traits, and are a ultimately a compromise between integrated aspects of the organism. Accordingly, the study of adaptation requires an understanding of how different traits constrain each other and how they are integrated to produce locally adapted phenotypes. There is only limited empirical evidence for how such constraints are manifested in real organisms. The proposed work will examine how selection acts on the integration of reproductive strategies, body shape, swimming performance, and behavior in natural populations of the guppy, Poecilia reticulata. The guppy is a model organism for the proposed work because it is one of the few organisms where adaptation has been documented. This previous work shows rapid adaptive changes in the reproductive traits of guppies in response to predatory fish. The work proposed here will first document the correlations among reproductive traits, body morphology, habitat use, foraging behavior, and stream type with field observations on female and male guppies from populations that are subject to different selection pressures. It will focus on the combined influences of stream current and predation. Because the reproductive traits of guppies are already known from these sites, the morphological and behavioral results obtained will provide the first data on whether body morphology, foraging behavior, habitat use, and reproductive strategies predictably covary with each other, or whether they vary independently in response to different selection pressures. Guppies will then be reared in the lab under different environments to test the degree to which these trait differences between populations represent fixed genetic differences or phenotypic plasticity. Finally, the proposed work will examine for the first time the consequences of pregnancy on body morphology and locomotion in an aquatic species by measuring how body profile and swimming performance change over the course of the reproductive cycle. Steady and escape swimming performance of gravid females from high and low predation localities will test the consequences of different reproductive allotments on locomotion and how adaptive changes in offspring number may compromise locomotion. By studying how reproductive strategies, morphology, locomotor performance, and behavior interact with each other and collectively respond to different selection pressures, the proposed work will provide a better understanding of the trade-offs faced by live-bearing fish adapting to their local environments.