Data from: Gene flow does not prevent personality and morphological differentiation between two blue tit populations

Understanding the causes and consequences of population phenotypic divergence is a central goal in ecology and evolution. Phenotypic divergence among populations can result from genetic divergence, phenotypic plasticity or a combination of the two. However, few studies have deciphered these mechanisms for populations geographically close and connected by gene flow, especially in the case of personality traits. In this study, we used a common garden experiment to explore the genetic basis of the phenotypic divergence observed between two blue tit (Cyanistes caeruleus) populations inhabiting contrasting habitats separated by 25 km, for two personality traits (exploration speed and handling aggression), one physiological trait (heart rate during restraint) and two morphological traits (tarsus length and body mass). Blue tit nestlings were removed from their population and raised in a common garden for up to five years. We then compared adult phenotypes between the two populations, as well as trait-specific Qst and Fst . Our results revealed differences between populations similar to those found in the wild, suggesting a genetic divergence for all traits. Qst - Fst comparisons revealed that the traits divergences likely result from dissimilar selection patterns rather than from genetic drift. Our study is one of the first to report a Qst - Fst comparison for personality traits and adds to the growing body of evidence that population genetic divergence is possible at a small scale for a variety of traits including behavioural traits.

解析种群表型分化的成因与效应，是生态学与进化生物学领域的核心研究目标之一。种群间的表型分化可由遗传分化、表型可塑性，或二者共同作用导致。然而，针对地理毗邻且存在基因流连通的种群，解析其表型分化具体机制的研究仍较为匮乏，针对性格性状（personality traits）的相关研究更是如此。本研究借助同质园实验（common garden experiment），针对2个性格性状（探索速度与处置攻击性）、1项生理性状（束缚状态下的心率）以及2项形态性状（跗跖长度与体质量），探究了两个相隔25km、栖息于迥异生境的青山雀（Cyanistes caeruleus）种群间表型分化的遗传基础。研究人员将青山雀雏鸟从原种群中移出，于同质园环境中饲养至最长5年。随后对两个种群的成体表型，以及各性状的Qst与Fst值进行了比较。研究结果显示，两个种群间的性状差异与野外观测到的差异一致，表明所有被测性状均存在遗传分化。Qst-Fst对比分析表明，各性状的分化更可能源于差异化的选择模式，而非遗传漂变。本研究是首批针对性格性状开展Qst-Fst对比分析的研究之一，同时为「包括行为性状在内的多种性状均可在小尺度范围内发生种群遗传分化」这一观点补充了愈发丰富的实证依据。