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

在这个项目中，Dochtermann博士和赫德里克博士将研究行为之间相关性的进化原因和后果。现在已经很好地理解了个体动物的行为通常是相关的，并且大多数以前的研究都集中在描述这些相关性。 很少有人关注为什么行为是相关的。对于为什么行为可能是相关的，通常有两种解释。首先，相关性可能存在，因为特定的行为组合在进化上是有利的（即选择）。第二，潜在的分子机制，如影响多种行为的单个基因，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塑造了相关性。在此之后，研究人员将进行一项人工选择实验，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的行为相关性。此外，这个实验将说明行为相关性影响和限制进化结果的程度，尽管行为综合征，个体行为相关性，现在在分类群中得到了很好的描述，但综合征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，以及分子机制，如多效性。这两类机制具有非常不同的进化含义。如果分子机制如多效性是综合征的基础，那么可能会限制SILD不存在的进化结果（重要的是，这些机制并不相互排斥，因为两者可能共同影响综合征的表达）。在这个项目中，研究人员将进行人口比较和人工选择实验，以区分这两类机制。具体而言，多个群体的遗传相关性和遗传力将估计和比较相对于生态变量。这些比较可以允许检测SILD，如果人口不同，选择压力可能有利于不同的组合行为之间的人口。后续的人工选择实验旨在打破行为相关性， 估计综合征的约束作用，以及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.