Evolutionary Genetic Architecture of Dispersal

分散是一个重要的生活史特征，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都假设这些性状存在显著的遗传变异，并与受自然选择影响的其他性状在遗传上共同变异。在理解扩散模式的演变过程中，一个主要的困难是无法量化影响扩散潜力的那些生物参数的个体差异。在海螺（Crepidula fornicata）中，控制扩散能力的主要生物学特性是自由游动的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，然后才能蜕变为静止的幼虫阶段。这段时间的强制性分散现在可以量化个体幼虫。我们建议确定与其他幼虫和变质后性状的数量遗传协方差，这些性状先前被认为会影响变质能力和适合度变异的发展。我们将特别测试这样一个假设，即扩散能力可能通过其与自然选择下的其他特征的遗传相关性而进化。

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.