Quantifying additive genetic variances and cross‐sex covariances in reproductive traits, and identifying processes that shape and maintain such (co)variances, is central to understanding the evolutionary dynamics of reproductive systems. Gene flow resulting from among‐population dispersal could substantially alter additive genetic variances and covariances in key traits in recipient populations, thereby altering forms of sexual conflict, indirect selection, and evolutionary responses. However, the degree to which genes imported by immigrants do in fact affect quantitative genetic architectures of key reproductive traits and outcomes is rarely explicitly quantified. We applied structured quantitative genetic analyses to multiyear pedigree, pairing, and paternity data from free‐living song sparrows (Melospiza melodia) to quantify the differences in mean breeding values for major sex‐specific reproductive traits, specifically female extra‐pair reproduction and male paternity loss, between recent immigrants and the previously existing population. We thereby quantify effects of natural immigration on the means, variances, and cross‐sex covariance in total additive genetic values for extra‐pair paternity arising within the complex socially monogamous but genetically polygynandrous reproductive system. Recent immigrants had lower mean breeding values for male paternity loss, and somewhat lower values for female extra‐pair reproduction, than the local recipient population, and would therefore increase the emerging degree of reproductive fidelity of social pairings. Furthermore, immigration increased the variances in total additive genetic values for these traits, but decreased the magnitudes of the negative cross‐sex genetic covariation and correlation below those evident in the existing population. Immigration thereby increased the total additive genetic variance but could decrease the magnitude of indirect selection acting on sex‐specific contributions to paternity outcomes. These results demonstrate that dispersal and resulting immigration and gene flow can substantially affect quantitative genetic architectures of complex local reproductive systems, implying that comprehensive theoretical and empirical efforts to understand mating system dynamics will need to incorporate spatial population processes.

中文翻译：

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最近的移民改变了麻雀亲子的定量遗传结构

量化生殖性状的加性遗传方差和变性性别协方差，并确定塑造和维持此类（共）方差的过程，对于理解生殖系统的进化动力学至关重要。种群间分散所产生的基因流可能会大大改变受体群体关键性状的加性遗传方差和协方差，从而改变性冲突，间接选择和进化反应的形式。但是，实际上很少明确量化移民输入的基因对关键生殖特征和结果的定量遗传结构的影响程度。我们将结构化的定量遗传分析应用于自由生活的麻雀（Melospiza melodia）的多年谱系，配对和亲子关系数据）量化最近移民与以前存在的人口之间主要性别生殖特征（尤其是雌对成对繁殖和男性父本丧失）的平均育种值的差异。因此，我们量化了自然移民对在复杂的一夫一妻但遗传上一夫多妻的生殖系统中产生的成对额外父本的总加成遗传值的均值，方差和性别交叉协方差的影响。与本地接受者相比，新移民的男性陪产假丧失平均育种价值较低，女性超配对繁殖的育种价值较低，因此将增加社交配对的生殖保真度。此外，移民增加了这些性状的总加成遗传值的差异，但将负性跨性别遗传协变和相关性的幅度降低到低于现有人群中明显的水平。因此，移民增加了总的遗传加性方差，但可能降低间接选择的程度，间接选择对父系结局对性别的贡献起作用。这些结果表明，扩散以及由此产生的移民和基因流动会极大地影响复杂的局部生殖系统的定量遗传结构，这意味着需要全面的理论和实证研究来了解交配系统的动态，需要纳入空间种群过程。因此，移民增加了总的遗传加性方差，但可能降低间接选择的程度，间接选择对父系结局对性别的贡献起作用。这些结果表明，扩散以及由此产生的移民和基因流动会极大地影响复杂的局部生殖系统的定量遗传结构，这意味着需要全面的理论和实证研究来了解交配系统的动态，需要纳入空间种群过程。因此，移民增加了总的遗传加性方差，但可能降低间接选择的程度，间接选择对父系结局对性别的贡献起作用。这些结果表明，扩散以及由此产生的移民和基因流动会极大地影响复杂的局部生殖系统的定量遗传结构，这意味着需要全面的理论和实证研究来了解交配系统的动态，需要纳入空间种群过程。