Evolutionary Genetic Architecture of Dispersal

扩散是一个主要的生活史特征，由许多相互作用的特征组成。大多数关于扩散模式进化的争论认为，这些性状存在显着的遗传变异，并且在遗传上与其他受自然选择影响的性状是相同的。理解扩散模式演变的一个主要困难是无法量化那些有助于扩散潜力的生物参数的个体差异。在海洋拖鞋蜗牛中，支配扩散能力的主要生物学特征是自由游动幼虫阶段的持续时间。Crepidula的幼虫必须在浮游生物中发育一到几个星期，才能蜕变到久坐的幼虫阶段。现在可以对单个幼虫的这一强制性散布时期进行量化。我们建议确定与其他幼虫和变态后性状的数量遗传协方差，这些性状先前已被提出影响变态能力和适合度变异的发展。我们将专门测试这一假设，即扩散能力可能通过其与自然选择的其他特征的遗传相关性来进化。

Dispersal is a major life history characteristic composed of many interacting traits. Most arguments about the evolution of dispersal patterns assume that there is significant genetic variation for these traits and genetically covary with other traits that are influenced by natural selection. A major difficulty in understanding the evolution of dispersal patterns has been the inability to quantify individual differences in those biological parameters contributing to dispersal potential. In the marine slipper snail, Crepidula fornicata, the principal biological trait governing dispersal capacity is the duration of a free-swimming larval stage. Larval of Crepidula must develop in the plankton for one to several weeks before becoming capable of metamorphosing to the sedentary juvenile stage. This period of obligatory dispersal can now be quantified for individual larvae. We propose to determine the quantitative genetic covariance with other larval and post-metamorphic traits that have been previously proposed to influence the development of metamorphic competence and fitness variation. We will specifically test the hypothesis that dispersal capacity may evolve through its genetic correlation with other traits that are subject to natural selection.