International Research Fellowship Program: Indirect Genetic Effects and the Evolution of Cannibalism

国际研究奖学金计划使美国科学家和工程师能够在国外进行9到24个月的研究。该项目的奖项提供了联合研究的机会，并利用国外独特或互补的设施、专业知识和实验条件。该奖项将支持Bronwyn H.Bleakley博士与英国埃克塞特大学的John Hunt和Allen Moore博士以及美国北亚利桑那州立大学的Stephen Shuster博士合作，为期24个月的研究奖学金。个人的行为可能不仅由其自身的基因和居住环境造成，也可能反映出个人的社会伴侣携带的基因。社会伴侣携带的基因对另一个个体行为的影响被称为“间接遗传效应”。间接遗传效应是产生“相互作用的表型”的一种方式，即个体的表型只能在相互作用的背景下描述。间接遗传效应被预测在社会行为的进化中特别重要，因为它们可能改变个体选择的方式，以及产生社会选择。社会选择的相对影响很少在自然人口中被分开，间接遗传效应对社会选择强度的影响从未被记录在案。食人行为是一种相互作用的表型，可能反映间接遗传效应，并被预测产生社会选择，但从未在这方面进行过探索。我们正在开发第一个描述间接遗传效应背景下同类相食进化的定量遗传模型，并利用一个自然系统--Socorro等足类动物--嗜热旋毛虫--对该模型进行实验测试。我们正在设计一个数量遗传模型，该模型考虑了个体大小和自相残杀的遗传方差和协方差，对这些性状进行的性别和社会选择的强度和方向，以及可能通过间接遗传效应影响这些性状的表达和进化的种内相互作用的频率和强度。我们正在使用该模型来数学操纵吃人和体型之间的遗传协方差结构，以及社会选择的强度，以预测这些因素对吃人进化速度的影响。我们正在同时获得对嗜热梭菌实验室种群中相互作用和非相互作用的特征(体型和自相残食)及其遗传方差和协方差的经验测量；产生对社会选择对这些等足目动物进化的相对影响的预测；并确定体型和自相残食之间的遗传协方差是否在现有的实验种群中有所不同，从而允许对选择的不同反应。

0700452BleakleyThe International Research Fellowship Program enables U.S. scientists and engineers to conduct nine to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad.This award will support a twenty-four-month research fellowship by Dr. Bronwyn H. Bleakley to work with Drs. John Hunt and Allen Moore at the University of Exeter in the United Kingdom, and with Dr. Stephen Shuster at Northern Arizona State University in the US.An individual's behavior may result not only from its own genes and the environment in which is resides, but may also reflect genes carried in the individual's social partners. The effects of genes carried in a social partner on the behavior of another individual are termed "indirect genetic effects." Indirect genetic effects are one way of generating "interacting phenotypes," where an individual's phenotype can only be described in the context of an interaction. Indirect genetic effects are predicted to be particularly important in the evolution of social behavior because they may alter the way selection operates on individuals, as well as generate social selection. The relative effects of social selection have only rarely been partitioned out in natural populations and the impacts of indirect genetic effects on the strength of social selection have never been documented. Cannibalistic behavior is an interacting phenotype, is likely to reflect indirect genetic effects, and is predicted to generate social selection, but has never been explored in this context. We are developing the first quantitative genetic model describing the evolution of cannibalism in the context of indirect genetic effects and utilizing a natural system, the Socorro Isopod Thermosphaeroma thermophilum, to experimentally test the model. We are designing a quantitative genetic model that considers the genetic variances and covariances underlying body size and cannibalism, the intensity and direction of sexual and social selection operating on these traits, and the frequency and strength of intraspecific interactions that may influence the expression and evolution of these traits via indirect genetic effects. We are using the model to mathematically manipulate the genetic covariance structure between cannibalism and body size and the intensity of social selection to predict the impact of these factors on the rate of evolution of cannibalism. We are concurrently obtaining empirical measurements of interacting and non-interacting traits (body size and cannibalism) and their genetic variances and covariances in lab populations of T. thermophilum; generating predictions for the relative influence of social selection on the evolution of these isopods; and determining if the genetic covariance between body size and cannibalism varies across existing experimental populations, allowing for differential response to selection.