DISSERTATION RESEARCH: A Multi-Locus Study of Genetic Impact of Rafting in North Atlantic Amphipods.

海洋遗传学的一个共同范例认为，具有自由生活的浮游生物幼虫的潮间带物种比直接发育成成虫的物种可以分散更远的距离。然而，这种模式并不总是正确的。事实上，许多没有自由生活的幼虫的物种确实能够分散很远的距离；这些物种可能通过依附于分离的藻类碎片（即漂流）而分散。人们已经观察到许多浅水海洋物种在离海岸相当远的海藻上漂流；然而，这些生物是否会到达另一个种群还不得而知。本研究的目的是确定漂流是否是没有自由生活幼虫的沿海海洋物种的有效传播手段。这项研究将集中在北大西洋的六种片脚类动物（小的，虾状的甲壳类动物，没有自由生活的幼虫）。两种是常见的椽子，两种是罕见的椽子，还有两种从未被观察到过。利用线粒体和核基因以及新开发的聚结分析方法，本研究将确定这些物种的基因流与漂流频率之间是否存在相关性。了解扩散对了解物种内部的遗传多样性至关重要。漂流是一种很少被研究的传播方式，因为在许多物种中，它与其他传播方式（如自由生活的幼虫）相混淆。这项资助将资助女研究生完成她的论文。

A common paradigm in marine genetics asserts that intertidal species with free-living, planktonic larvae can disperse longer distances than species that develop directly into adults. This pattern, however, does not always hold true. In fact, many species without free-living larvae do manage to disperse long distances; these species may be dispersing by clinging to detached pieces of algae (i.e. rafting). Many shallow-water marine species have been observed rafting on algae quite far from shore; whether these organisms ever reach another population, however, is unknown. The goal of this study is to determine whether rafting is an effective means of dispersal for coastal marine species without free-living larvae. This study will focus on six species of amphipods (small, shrimp-like crustaceans that lack free-living larvae) in the North Atlantic. Two species are common rafters, two are rare rafters, and two have never been observed rafting. Using mitochondrial and nuclear genes and newly-developed coalescent methods of analysis, this study will determine whether there is a correlation between gene flow and rafting frequency in these species. Understanding dispersal is crucial to understanding genetic diversity within species. Rafting is a means of dispersal that has rarely been studied, as in many species it is confounded by other dispersal methods such as free-living larvae. This grant will provide funding for a female graduate student to finish her dissertation.