Collaborative Research: Genome-Scale Phylogeographic Analysis of Desmognathus Salamanders

达斯基火蜥蜴是美国东部森林中种类最多、数量最多的动物之一。它们是生态学和行为学的经典研究有机体。与世界各地的青蛙和其他火蜥蜴一样，它们也在以惊人的速度消失，可能是由于栖息地丧失、传染病和其他环境压力等因素。尽管它们的能见度和危害性很大，但我们对它们的遗传多样性和进化史知之甚少。虽然目前只有21个命名物种，但最近使用DNA测序的工作已经揭示了至少45个潜在物种，这将使该物种的规模增加一倍以上。这项研究将揭示该种群的真实多样性，为未来的Desmognatus生态和进化研究提供一个平台，并指导这一濒危水生脊椎动物种群的保护和管理决策。更广泛的影响将包括一个以火蜥蜴为中心的K-12森林生态学教学模块，以及为当地野生动物管理当局更新物种账户。这对于了解美国的生物多样性遗产将是无价的。这项研究将利用一种详尽的“生态排水”采样技术，分析几乎每一个已知的豆科动物种群的7000个样本。这项研究将使用下一代DNA基因组测序来了解该群体的真实遗传多样性。这些数据将使研究人员能够使用现代物种划分方法，从遗传角度理解分化、杂交和物种边界的进化史。许多物种也很难用肉眼区分开来。因此，这项研究将用大小和形状的三维几何形态计量学分析来补充遗传角度，以揭示种群之间微妙但显著的形态差异。总体而言，这项研究将产生一个可靠的和完全抽样的估计，以真实的数量，它们的形态变异，以在野外识别它们，以及它们的地理范围。这项研究可能会产生更多的Desmognatus物种，同时也显示出该群体中的渗入、杂交和不完全生态物种形成的复杂历史。

The Dusky Salamanders, genus Desmognathus, are one of the most diverse and abundant animals in the eastern forests of the United States. They are classic study organisms for ecology and behavior. Along with frogs and other salamanders worldwide, they are also disappearing at an alarming rate, possibly due to factors such as habitat loss, infectious diseases, and other environmental stresses. Despite their visibility and imperilment, we know little about their genetic diversity and evolutionary history. While there are only 21 currently named species, recent work using DNA sequencing has revealed at least 45 potential species, which would more than double the size of the group. This research will reveal the true diversity of the group, providing a future platform for ecological and evolutionary studies of Desmognathus, and guiding conservation-management decisions for this imperiled group of aquatic vertebrates. Broader impacts will include a K-12 teaching module for understanding forest ecology, centered on salamanders, and updated species accounts for local wildlife-management authorities. This will be invaluable for understanding the biodiversity heritage of the United States.With an exhaustive "ecodrainage" sampling technique, this research will analyze 7,000 samples from nearly every known Desmognathus population. The study will use next-generation genomic sequencing of DNA to understand the true genetic diversity of the group. These data will allow researchers to understand the evolutionary history of divergence, hybridization, and species boundaries from a genetic perspective, using modern species-delimitation methods. Many species are also difficult to distinguish by eye. Thus, this research will complement the genetic perspective with 3-dimensional geometric morphometric analyses of size and shape, to reveal the subtle but significant morphological differences between populations. Overall, this research will generate a robust and fully-sampled estimate of the true number of Desmognathus species, their morphological variation for identifying them in the field, and their geographic range. This research will likely yield an increased number of Desmognathus species, while also showing a complex history of introgression, hybridization, and incomplete ecological speciation in the group.