Social drivers of extra-pair paternity

同一种群的个体间额外配对亲子关系(EPP)表达的差异可能是随机人口统计学或交配策略的个体差异造成的。虽然EPP的适应价值已经得到了广泛的研究，但对于驱动EPP观察到的模式的社会环境特征还知之甚少。我建议调查影响人口中EPP水平的个人所处的社会环境的特征。我假设，社会属性，如个体之间的联系程度和社会纽带的强度，可以解释额外配对交配(EPC)和EPP模式的变化，个人的社会性受到遗传机制的影响。我建议使用两个家雀选育品系(具有低和高EPP水平)，以及最近来自野生的品系(非常低EPP)，在三年的重复实验中，表征和比较EPP的社会行为和模式。首先，我将使用最先进的跟踪技术与社会网络分析相结合，在三个层面上量化社会互动的方向性和群体的社会结构：个人(例如程度)、二元(例如力量)和群体(例如表型群体组成)；我将使用亲子关系分析来确定遗传交配模式。然后，我将使用线性混合模型来确定社会属性与EPP和EPC水平之间的关系，并使用动物模型来量化社会特征的遗传力。通过了解社会环境和交配系统之间的相互作用，我将有助于解释驱动种群内EPP变异的最接近的机制，并最终理解交配系统的进化和维持。

Variation in the expression of extra-pair paternity (EPP) among individuals of the same population could result from stochastic demography or from individual differences in mating strategies. Although the adaptive value of EPP has been widely studied, little is yet known about the characteristics of the social environment that drive the observed patterns of EPP. I propose to investigate the characteristics of the social environment in which individuals are embedded that influence the levels of EPP in a population. I hypothesise that social attributes such as degree of connection among individuals and the strength of social bonds can explain the variation in the patterns of extra-pair copulations (EPCs) and EPP, and that the sociality of individuals is influenced by genetic mechanisms. I propose to use two selection lines of domestic zebra finches (with low and high EPP levels), along with a recently wild-derived line (very low EPP) to characterize and compare the social behaviour and patterns of EPP, in replicated experiments, over the course of three years. First, I will use state-of the-art tracking technologies in combination with social network analyses to quantify the directionality of the social interactions and the social structure of the groups at three levels: individual (e.g. degree), dyad (e.g. strength) and group (e.g. phenotypic group composition); and I will use parentage analysis to determine the genetic mating patterns. Then, I will use linear mixed models to determine the relationship between social attributes and levels of EPP and EPCs and animal models to quantify the heritability of social traits. By understanding the interplay between the social environment and the mating systems I will contribute to the explanation of the proximate mechanisms that drive variation in EPP within populations, and ultimately to understand the evolution and maintenance of mating systems.