Collaborative Research: Behavioral Syndromes as Evolutionary Constraints: the Role of Genetic Architecture

在这个项目中，dr。Dochtermann和Hedrick将研究行为之间相关性的进化原因和结果。现在人们已经很清楚，单个动物的行为往往是相关的，而大多数先前的研究都集中在描述这些相关性上。人们很少关注行为为何相关。通常有两种解释可以解释为什么行为可能是相关的。首先，相关性可能存在，因为特定的行为组合在进化上得到了青睐（即选择）。其次，潜在的分子机制，如单个基因影响多种行为，可能会产生相关性。通过比较种群之间的遗传相关性，pi将试图了解选择是否形成了相关性。在此之后，研究人员将进行人工选择实验，目的是打破行为相关性。这个人工选择实验将提供额外的证据，说明上述任何一种解释可能产生行为相关性的程度。此外，该实验将说明行为相关性影响和约束进化结果的程度。虽然行为综合症，在个体行为的相关性中，现在已经很好地描述了整个分类群，但综合症的进化原因和后果仍然知之甚少。综合征的进化原因通常可以分为两类机制：选择诱导的连锁不平衡（SILD），其中特定的行为组合受到青睐，以及多效性等分子机制。这两类机制具有非常不同的进化意义。如果多效性等分子机制是综合征的基础，那么可能会对SILD不存在的进化结果施加限制（重要的是，这些机制不是相互排斥的，因为两者都可能共同影响综合征的表达）。在这个项目中，研究人员将进行种群比较和人工选择实验来区分这两类机制。具体地说，多个种群的遗传相关性和遗传力将相对于生态变量进行估计和比较。如果种群之间存在差异，选择压力可能倾向于种群之间不同的行为组合，这些比较可以检测到SILD。后续的人工选择实验旨在打破行为相关性，将评估综合征的约束效应，而群体对人工选择的反应能力将区分SILD和分子机制。

In this project, the Drs. Dochtermann and Hedrick will study the evolutionary causes and consequences of correlations among behaviors. It is now well understood that the behaviors of individual animals are often correlated, and most previous research has focused on characterizing these correlations. Much less attention has been paid to understanding why behaviors are correlated. There are generally two explanations for why behaviors might be correlated. First, correlations might be present because particular combinations of behaviors have been evolutionarily favored (i.e. selection). Second, underlying molecular mechanisms,such as a single gene affecting multiple behaviors,might produce correlations. By comparing genetic correlations among populations, the PIs will attempt to see if selection has shaped correlations or not. Following this, the researchers will conduct an artificial selection experiment with the aim of breaking apart behavioral correlations. This artificial selection experiment will provide additional evidence regarding the degree to which either of the above explanations might produce behavioral correlations. Moreover, this experiment will illustrate the degree to which behavioral correlations affect and constrain evolutionary outcome.Although Behavioral Syndromes, among-individual behavioral correlations, are now well described across taxa, the evolutionary causes and consequences of syndromes are still poorly understood. The evolutionary causes of syndromes can generally be grouped into two classes of mechanisms: selection-induced linkage disequilibrium (SILD) wherein particular combinations of behaviors have been favored, and molecular mechanisms such as pleiotropy. These two classes of mechanisms have very different evolutionary implications. If molecular mechanisms such as pleiotropy underlie syndromes, then constraints may be placed on evolutionary outcomes which are not present with SILD (importantly, these mechanisms are not mutually exclusive, as both may jointly influence the expression of syndromes). In this project, the researchers will conduct population comparisons and artificial selection experiments to distinguish between these two classes of mechanisms. Specifically, genetic correlations and heritabilities of multiple populations will be estimated and compared relative to ecological variables. These comparisons can allow the detection of SILD if the populations differ such that selective pressures might favor different combinations of behaviors among populations. Follow up artificial selection experiments designed to break apart behavioral correlations will estimate the constraining effect of syndromes, and the ability of populations to respond to artificial selection will distinguish between SILD and molecular mechanisms.