Collaborative Research: Genome-Scale Phylogeographic Analysis of Desmognathus Salamanders

暗色蝾螈，Desmognathus属，是美国东部森林中最多样化和最丰富的动物之一。它们是生态学和行为学的经典研究生物。沿着全世界的青蛙和其他蝾螈，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。尽管它们的可见性和危险性，我们对它们的遗传多样性和进化历史知之甚少。虽然目前只有21个命名的物种，但最近使用DNA测序的工作揭示了至少45个潜在的物种，这将使该群体的规模增加一倍以上。这项研究将揭示该群体的真实多样性，为Desmognathus的生态和进化研究提供未来的平台，并指导这一濒危水生脊椎动物群体的保护管理决策。更广泛的影响将包括一个K-12教学模块，用于了解森林生态，以蝾螈为中心，并为当地野生动物管理当局更新物种账户。这将是非常宝贵的了解美国的生物多样性遗产。与详尽的“生态排水”采样技术，这项研究将分析7,000个样本，从几乎每一个已知的Desmognathus种群。该研究将使用下一代DNA基因组测序来了解该群体的真正遗传多样性。这些数据将使研究人员能够使用现代物种划界方法，从遗传学的角度了解分歧，杂交和物种边界的进化历史。许多物种也很难用眼睛区分。因此，这项研究将补充遗传的角度与三维几何形态测量分析的大小和形状，揭示微妙的，但显着的形态差异种群之间。总的来说，这项研究将产生一个强大的和完全抽样的估计Desmognathus物种的真实数量，它们的形态变化，以确定他们在外地，他们的地理范围。这项研究可能会产生更多的Desmognathus物种，同时也显示了一个复杂的历史的渐渗，杂交和不完整的生态物种形成的组。

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.