DISSERTATION RESEARCH: Detecting ecomorphological convergence in the salamander genus Desmognathus: A phylogenetic approach using molecular and geometric morphometric analyses

论文研究：检测蝾螈属 Desmognathus 的生态形态趋同：使用分子和几何形态计量分析的系统发育方法

• 批准号: 0808451
• 负责人: Alfred Lamb
• 金额: $ 1.19万
• 依托单位: East Carolina University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-07-15 至 2010-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0808451&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Detecting; ecomorphological; convergence

The dusky salamander genus Desmognathus is a species-rich group of amphibians distributed across eastern North America. Although many species occupy deciduous forest streams, the group demonstrates remarkable ecological breadth, ranging in habitats from spruce forests to coastal swamps. Despite their ecological diversity, the species of dusky salamanders are quite similar in appearance and all share a pattern of brown, mottled markings that makes species identification notoriously difficult. As a result, interpretations regarding the exact number of species (and relationships among them) remain controversial and problematic. This study will work to resolve evolutionary relationships of dusky salamanders by: 1) sampling salamanders on a very fine geographic scale, and 2) assessing variation among these sampled populations using molecular characters (DNA sequences for several genes) as opposed to morphological characters. Preliminary results confirm the validity of certain species but also have revealed additional, undescribed species. Moreover, preliminary work using a new geometric approach to morphological analysis suggests that subtle variation in head shape may play an important role in the group's observed ecological diversity by allowing various species of dusky salamanders to forage in slightly different ways. This study will generate a large database including several thousand specimens (to be deposited in the Field Museum of Natural History, Chicago) and DNA sequences (to be deposited in Genbank), which will be available to biologists worldwide. The fine-scale sampling will help to identify all species in the group and delimit their geographic distributions, findings important to conservation and land management.

Desmognathus是一个物种丰富的两栖动物群，分布在北美东部。虽然许多物种占据落叶林溪流，该集团表现出显着的生态广度，从云杉林到沿海沼泽的栖息地。尽管它们的生态多样性，暗蝾螈的物种在外观上非常相似，都有一种棕色斑驳的斑纹，这使得物种识别非常困难。因此，关于物种的确切数量（以及它们之间的关系）的解释仍然存在争议和问题。这项研究将致力于解决暗蝾螈的进化关系：1）在一个非常精细的地理尺度上对蝾螈进行采样，2）使用分子特征（几个基因的DNA序列）而不是形态特征来评估这些采样种群之间的变异。初步结果证实了某些物种的有效性，但也发现了其他未描述的物种。此外，初步工作使用一种新的几何方法形态分析表明，头部形状的微妙变化可能会发挥重要作用，在该组的观察到的生态多样性，使不同种类的dusky蝾螈觅食略有不同的方式。 这项研究将产生一个大型数据库，其中包括几千个标本（将存放在芝加哥菲尔德自然历史博物馆）和DNA序列（将存放在基因库），全世界的生物学家都可以使用。细尺度取样将有助于确定该组中的所有物种，并划定其地理分布范围，这对保护和土地管理具有重要意义。