REU: Phenotypic Diversification in Gasterosteus

在最后一次更新世冰川推进期间，冰覆盖了三刺鱼(Gastersteus Aculeatus)现代活动范围的大部分。大约14,000年前，随着冰川开始消退，各种淡水栖息地被创造出来，随后被海洋刺鱼殖民。今天，在整个北美西北部，由此产生的淡水种群正在经历快速的进化多样化，在某些情况下，物种形成已经发生。这种不同寻常的、最近的辐射为提供关于进化变化的模式和机制的信息带来了巨大的希望。它还为具有新属和更高分类群的适应性辐射提供了一个模型。这项拟议的研究将首次确定海洋三刺鱼表现出的生殖行为模式，以及它们在不同地点之间的差异程度。这对于解释辐射的变化模式是至关重要的，因为海洋形态被认为是导致今天观察到的不同淡水形态的原因。此外，还将记录20个或更多阿拉斯加淡水种群的生殖行为多样性。这些观察不仅将提供阿拉斯加淡水种群行为多样化范围的初步近似值，还将使研究人员能够选择种群，用于未来对特定行为表型进化的研究。

During the last Pleistocene glacial advance, ice covered much of the modern day range of the threespine stickleback (Gasterosteus aculeatus). As the glaciers began to retreat about 14,000 years ago, a diversity of freshwater habitats were created and subsequently colonized by the marine threespine stickleback. Today, the resultant freshwater populations are undergoing rapid evolutionary diversification throughout northwestern North America, and in some cases speciation has occurred. This remarkable, recent radiation holds great promise for providing information on the patterns and mechanisms of evolutionary change. It also provides a model for adaptive radiations that have new genera and higher taxa. The proposed research will determine, for the first time, the reproductive behavior patterns exhibited by marine threespine stickleback, and the extent to which they vary among sites. This is essential for interpreting the patterns of change in the radiation because the marine form is thought to have given rise to the divergent freshwater forms observed today. In addition, the diversity of reproductive behavior in twenty or more Alaskan freshwater populations will be documented. These observations will not only provide a first approximation of the range of behavioral diversification among Alaskan freshwater populations, but will enable the investigators to select populations for future research on the evolution of specific behavioral phenotypes.