Dissertation Research: How Do Stepping-stones of Available Habitat Affect Genetic Connectivity in Neritid Snails?

大多数海洋生物与陆地生物有很大的不同，因为它们将大量的后代分散到洋流中作为微小的幼虫，以寻找合适的生活场所。今天海洋生物学的一个主要焦点是试图了解这个“黑匣子”，即幼虫在哪里以及如何传播，因为这对理解和保护海洋动物和植物具有重要意义。本研究的目的是为了更好地了解栖息地的“垫脚石”的作用，通过幼虫扩散连接遥远的种群彼此。这一目标将通过比较能够利用无水环礁作为踏脚石的海洋蜗牛物种与不能利用无水环礁作为踏脚石的淡水近亲的种群遗传学来实现。据推测，海洋物种的种群之间的联系要比淡水物种的种群之间的联系更好，尽管两者都有海洋幼虫。长期以来，人们一直认为渔业和海洋生物种群是取之不尽的，因为它们总是可以从其他地方得到补充。最近许多渔业的崩溃，加上最近对海洋种群遗传学的研究，都表明情况并非如此;幼虫可能经常返回其出生地，或仅分散一小段距离。如果是这样的话，重要的是建立网络中的海洋保护区，使它们足够接近，以“捕捉”从邻近保护区传播的幼虫，其方式类似于陆地绿地或走廊的功能。了解天然海洋垫脚石的工作方式对这一努力至关重要。

Most marine organisms are very different from terrestrial organisms in that they disperse their numerous offspring into ocean currents as tiny larvae to find a suitable place to live. A major focus of marine biology today is to try to see into this "black box" of where and how larvae disperse, as this has significant consequences for understanding and conserving marine animals and plants. The goal of this study is to better understand the role of "stepping-stones" of habitat in connecting distant populations to each other through larval dispersal. This goal will be achieved through a comparison of the population genetics of marine snail species that are able to use waterless atolls as stepping-stones to those of their close freshwater relatives that cannot. It is hypothesized that populations of the marine species will be better connected to one another than populations of freshwater species even though both have marine larvae.It has long been assumed that fisheries and populations of marine organisms were inexhaustible because they could always be replenished from elsewhere. The recent collapse of many fisheries, combined with recent studies of marine population genetics, have shown that this is not the case; larvae may often return to their birthplace, or only disperse for a short distance. If this is so, it will be important to set up marine reserves in networks so that they are close enough together to "catch" larvae that disperse from neighboring reserves in a manner that is similar to the function of terrestrial greenbelts or corridors. An understanding of how natural marine stepping-stones work will be important to this effort.