Phenotypic traits partly determine expected survival and reproduction, and so have been used as the basis for demographic models of population dynamics. Within a population, the distribution of phenotypic traits depends upon their transmission from parents to offspring, yet we still have a limited understanding of the factors shaping phenotypic transmission in wild populations. Phenotypic transmission can be measured using the phenotypic parent–offspring correlation (C), defined as the slope of the regression of offspring phenotypic trait on parental phenotypic trait, both traits measured at the same age, often at birth. This correlation reflects phenotypic variation due to both additive genetic effects and parental effects. Researchers seldom account for the possible influence of selection on estimates of the phenotypic parent–offspring correlation. However, because individuals must grow, survive, and reproduce before giving birth to offspring, these ,aphic processes might influence the phenotypic parent–offspring correlation in addition to the inheritance process, the latter being the direct relationship between parental and offspring phenotypic traits when the parental trait is measured at age of reproduction and the offspring trait is measured at birth. Here we used a female-based population model to study the relative effects of fertility and viability selections, trait ontogeny and inheritance on C. The relative influence of each demographic process is estimated by deriving the exact formulas for the proportional changes in C to changes in the parameters of integral projection models structured by age and phenotypic traits. We illustrate our method for two long-lived species. We find that C can be strongly affected by both viability and fertility selections, mediated by growth and inheritance. Generally, demographic processes that result in mothers reproducing at similar phenotypic traits regardless of their birth traits, such as high fertility selection or converging developmental trajectories, lead to a decreased C. More generally, our models show how the age and phenotypic dependence of fertility and viability selections can influence phenotypic mother–offspring correlation to a much larger extent than ontogeny and inheritance. Our results suggest that accounting for such dependence is needed to model the distribution of offspring phenotypic traits and the ecoevolutionary dynamics of phenotypic traits reliably.

中文翻译：

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表型母子相关性的人口统计学决定因素

表型特征部分决定了预期的生存和繁殖，因此已被用作人口动态人口模型的基础。在一个种群中，表型性状的分布取决于它们从父母到后代的传递，但我们对野生种群中表型传递的影响因素的理解仍然有限。表型传递可以使用表型亲代-后代相关性 (C) 来衡量，定义为后代表型性状对亲本表型性状的回归斜率，这两种性状通常在出生时测量。这种相关性反映了由于加性遗传效应和亲本效应造成的表型变异。研究人员很少考虑选择对表型亲代相关性估计的可能影响。然而，由于个体在生下后代之前必须生长、生存和繁殖，这些无非性过程除了影响遗传过程之外，还可能影响表型亲代相关性，后者是亲代和后代表型性状之间的直接关系。父母的性状是在繁殖年龄时测量的，后代性状是在出生时测量的。在这里，我们使用基于女性的种群模型来研究生育力和生存力选择、性状个体发育和遗传对 C. 每个人口统计过程的相对影响是通过推导 C 的比例变化与年龄和表型特征构成的积分投影模型参数变化的精确公式来估计的。我们说明了我们对两个长寿物种的方法。我们发现 C 可以受到由生长和遗传介导的生存力和生育力选择的强烈影响。一般来说，导致母亲以相似的表型特征繁殖而不管其出生特征（例如高生育率选择或收敛的发育轨迹）的人口统计过程导致 C 降低。与个体发育和遗传相比，生存能力选择可以在更大程度上影响表型母子相关性。