Social Learning and Sexual Selection in Field Crickets

这项建议涉及进化生物学中关于通过性选择起源和维持生物多样性的一个中心概念。通过雌性选择的性选择可以加速不同种群的生殖隔离，它在推动男性装饰品的精加工和维护方面的作用得到了理论和经验的支持。性选择的所有理论框架都依赖于女性偏好和男性装饰品的遗传基础。然而，一些非遗传因素已经引起了研究人员的注意，因为它们对性选择的强度和方向有潜在的巨大影响。其中之一最近引起了人们的注意：女性择偶的可塑性。择偶是一个过程，女性通过这个过程来评估可用的男性的吸引力，并决定与谁交配。择偶可塑性是指个体交配行为受环境因素影响的灵活性。这项建议的重点是从同类细节中学习的社会信息如何有助于配偶选择的这种灵活性，我最终感兴趣的是配偶选择的变化如何反馈到改变男性特征上的选择压力。我的研究将使用昆虫系统，因为尽管昆虫被广泛用作性别选择研究的模型，但关于社会学习如何影响昆虫配偶选择和性选择的信息缺乏。我将使用波利尼西亚田野板球Teleoggrlus Ocean anicus来探索这一富有成效的研究途径。我将研究社会习得的配偶选择可塑性在人群水平上的差异，它的遗传基础和对个体的适应效应，以及它对男性特征的性选择压力的更广泛的影响。我在加州大学河滨分校所做的博士后研究表明，雌性蟋蟀可以记住有关召唤雄性蟋蟀的吸引力的信息，并利用这些信息来改变随后的交配决定。有了这个基础，我的第一个目标是调查在整个人口范围内配偶选择可塑性变化的程度。理论论证表明，在新环境中创建的种群将被选择来表现出更大程度的适应性表型可塑性。新成立的群体的社会环境预计会有一定的变化，我将检验这样一个假设，即新成立的群体(使用群体遗传数据推断)显示出更大程度的社会中介择偶可塑性。其次，我将进行一项定量的遗传交配实验，以检测雌性通过改变交配行为来应对不同社会环境的倾向的遗传变异。我的分析将检测不同遗传背景的女性是否对社会经历表现出不对称的行为反应。这将揭示选择作用于社会中介的配偶选择可塑性的可能性，这取决于它的加性遗传变异的大小。第三，我将研究社会中介的择偶可塑性在这一领域的健康后果。这一分析将为社会影响如何改变野外的性选择压力提供关键的见解，这一点迄今尚未在实证研究中得到解决。最后，我将开发包含社会中介的择偶可塑性的性选择的定量遗传模型，以测试这种可塑性如何改变性选择的结果。理论模型将解决相反的假设，即配偶选择中的经验中介可塑性可以加强或弱化性选择，并将探索关于配偶选择可塑性的选择是否可以驱动种群之间生殖障碍的进化的问题。

This proposal addresses a central concept in evolutionary biology regarding the origin and maintenance of biological diversity through sexual selection. Sexual selection via female choice can accelerate reproductive isolation in diverging populations, and its role in driving the elaboration and maintenance of male ornaments is supported theoretically and empirically. All theoretical frameworks for sexual selection rely on the genetic basis of female preferences and male ornaments. However, a number of non-genetic factors have captured the attention of researchers because of their potentially large effects on the strength and direction of sexual selection. One of these has recently gained attention: plasticity in female mate choice. Mate choice is the process by which females evaluate the attractiveness of available males and make a decision about who to mate with. Mate choice plasticity refers to flexibility in individual mating behavior that is influenced by environmental factors. This proposal focuses on how social information learned from conspecifics contributes to such flexibility in mate choice, and I am ultimately interested in how changes in mate choice feed back to alter selection pressure on male traits. My research will use an insect system, because although insects are extensively used as models in sexual selection studies, information about how social learning affects insect mate choice and sexual selection is lacking. I will pursue this fruitful avenue of inquiry using the Polynesian field cricket Teleogryllus oceanicus. I will investigate population-level variation in socially-learned mate choice plasticity, its genetic basis and fitness effects on individuals, and its broader implications for sexual selection pressure on male traits. My postdoctoral work at the University of California, Riverside has established that female crickets can retain information about the attractiveness of calling males and use that information to alter subsequent mating decisions. Given this foundation, my first goal is to investigate the extent to which mate choice plasticity varies on a population-wide scale. Theoretical arguments suggest that founding populations in new environments will be selected to exhibit a greater degree of adaptive phenotypic plasticity. The social environment of newly-founded populations would be expected to vary stochoastically, and I will test the hypothesis that more recently founded populations (inferred using population genetic data) show a greater degree of socially-mediated mate choice plasticity. Second, I will perform a quantitative genetic mating experiment to detect genetic variation in the tendency of females to respond to different social environments by altering their mating behavior. My analysis will detect whether females of different genetic backgrounds show asymmetrical behavioral responses to social experience. This will reveal the potential for selection to act on socially-mediated mate choice plasticity, which depends on the magnitude of additive genetic variation for it. Third, I will examine fitness consequences of socially-mediated mate choice plasticity in the field. This analysis will lend key insights into how social effects alter sexual selection pressure in the wild, which has not been addressed in empirical studies to date. Finally, I will develop quantitative genetic models of sexual selection that incorporate socially-mediated mate choice plasticity, to test how such plasticity alters the outcome of sexual selection. The theoretical models will address the opposing hypotheses that experience-mediated plasticity in mate choice can strengthen vs. weaken sexual selection, and will explore the question of whether selection on mate choice plasticity can drive the evolution of reproductive barriers between populations.