Collaborative Research: Species delimitation in North American lizards

物种是自然界多样性的基本单位。因此，准确记录物种多样性在生命科学、栖息地管理和保护方面具有重要意义。然而，尽管物种在理解生物多样性方面的重要性，但在许多分类学群体中往往很难确定明确的物种边界。蜥蜴就是一个这样的例子，一个分类组具有遗传上不同的种群，往往看起来非常相似。看起来是一种蜥蜴的物种往往是几种可能的蜥蜴物种的物种群。在这个项目中，研究人员将与15个不同机构的科学家合作，确定北美蜥蜴30个物种组的物种边界。这样做将（1）将物种如何形成的科学理解与命名物种的实践联系起来，（2）建立一个知识和方法框架，以便在其他分类学群体中一致地命名物种。研究人员将在三个大都市地区的社区活动中分享他们的研究成果，让本科生参与真实的研究，并指导分类修订以促进稳定的物种名称。该项目将使用综合方法来划分物种。首先，项目小组将与分类学专家合作，为每个重点物种组进行全范围的遗传、生态和形态取样。然后将对这些数据进行一致的分析，以表征每个物种复合体内的遗传和表型差异水平。然后，项目小组将通过使用遗传数据来测量候选物种之间的杂交和渐渗程度，从而分析候选物种之间的生殖隔离水平。通过比较分歧和隔离的数据，研究小组将描述生殖隔离演变的速度和步伐。利用这些估计数，该小组将确定种群-物种边界，并将其应用于30个重点群体，以确定随着时间的推移显示出最高持久性的分类单位。最后，利用修订的分类法，该小组将评估仅根据遗传数据定义分类单位的物种划界方法。虽然这些方法是有效的，但也可能存在偏差，本分析将确定这些偏差的潜在原因。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Species are a fundamental unit of diversity in the natural world. Therefore, accurately documenting species diversity has important implications in life sciences, habitat management, and conservation. Yet, despite the importance of species in understanding biodiversity, it is often difficult to identify unambiguous species boundaries in many taxonomic groups. Lizards are one such example of a taxonomic group with genetically-different populations that often look very similar. What appears to be one lizard species is often a species group of several possible lizard species. In this project, the researchers will collaborate with scientists across 15 different institutions to determine species boundaries in 30 species groups of North American lizards. Doing so will (1) connect scientific understandings of how species form to the practice of naming species and (2) model an intellectual and methodological framework for naming species consistently in other taxonomic groups. The researchers will share their research findings at community events across three metropolitan regions, engage undergraduate students in authentic research, and guide taxonomic revisions to promote stable species names.This project will use an integrative approach to delimit species. First, the project team will collaborate with taxonomic experts to generate range-wide genetic, ecological, and morphological sampling for each focal species group. These data will then be analyzed consistently to characterize levels of genetic and phenotypic divergence within each species complex. Then, the project team will assay levels of reproductive isolation between candidate species by using genetic data to measure the extent of hybridization and introgression between them. By comparing data on divergence and isolation, the team will characterize the rate and pace at which reproductive isolation evolves. Using these estimates, the team will then define the population-species boundary and apply it to the 30 focal groups to identify taxonomic units that show the highest levels of durability through time. Finally, using the revised taxonomy, the team will evaluate species delimitation methods that define taxonomic units based solely on genetic data. While efficient, these methods can be biased, and this analysis will identify the potential causes for these biases.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.