A function-valued trait approach to estimating the genetic basis of size at age and its potential role in fisheries induced evolution

Natural selection is inherently a multivariate phenomenon. The selection pressure on size (natural and artificial) and the age at which selection occurs is likely to induce evolutionary changes in growth rates across the entire life history. However, the covariance structure that will determine the path of evolution for size-at-age has been studied in only a few fish species. We therefore estimated the genetic covariance function for size throughout ontogeny using Atlantic silversides (Menidia menidia) as the model system. Over a 3-year period, a total of 542 families were used to estimate the genetic covariance in length at age from hatch through maturity. The function-valued trait approach was employed to estimate the genetic covariance functions. A Bayesian hierarchical model was used to account for the unbalanced design, unequal measurement intervals, unequal sample sizes, and family-aggregated data. To improve mixing, we developed a two-stage sampler using a Gibbs sampler to genera...

自然选择本质上属于多变量现象。针对体型的自然与人工选择压力，以及选择作用发生的年龄，大概率会引发整个生活史阶段生长速率的演化改变。然而，目前仅在少数鱼类物种中，针对决定年龄-体型演化路径的协方差结构开展了相关研究。因此本研究以大西洋银汉鱼（*Menidia menidia*）为模式系统，估算了个体发育全过程中体型的遗传协方差函数。在为期3年的研究周期内，共计使用542个家系，估算了从孵化至成熟阶段各年龄对应的体长遗传协方差。本研究采用函数值性状（function-valued trait）分析方法估算遗传协方差函数。采用贝叶斯分层模型来处理非平衡实验设计、不等测量间隔、样本量不均以及家系汇总数据等问题。为提升采样混合性，本研究搭建了基于吉布斯采样器（Gibbs sampler）的两阶段采样框架，以进行……