Collaborative research: Species delimitation, hybridization and the origin of parthenogenesis in Whiptail lizards (Aspidoscelis).

物种是生物多样性的基本单位。科学家必须能够准确地识别物种之间的界限，以及它们之间的关系，以了解基本的生物过程和生物多样性的全球模式。某些生物体的生物学特性使识别物种变得困难。特别是，当物种在自然界中杂交时，它模糊了科学家通常用来识别它们的形态和遗传变异模式。在某些情况下，杂交还与独特而有趣的生物现象有关，例如生殖模式、染色体数目或进化适应的变化。在这个项目中，研究小组将开发方法来准确识别一组蜥蜴的物种，其中杂交是常见的，物种鉴定一直具有挑战性：北美和中美洲鞭尾蜥蜴属Aspidoscelis。除了改进识别物种的方法外，这项研究还将增加对野生杂交影响的理解，以及这类蜥蜴生殖模式的进化。这些研究活动还将为一个由科学家和学生组成的多元化团队提供培训，其中许多人来自通常在科学领域代表性不足的群体，地点在夏威夷和加州。鞭尾的多样性非常快，并且经历了大量的渐进杂交，这使它们成为评估系统发育和群体遗传方法的理想选择，用于解纠缠杂交、谱系分类和系统误差。雌雄同体物种之间的杂交也多次导致单性生殖谱系的形成，其频率基本上是这一群体所独有的。研究小组将使用基因组和形态学数据来解开渐进杂交和谱系分类对鞭尾蜥所有谱系分化模式的影响，并利用这些结果来推断整个属的孤雌生殖的起源。通过研究鞭尾杂交和基因渗入的地理、时间和基因组动态，该项目将更好地了解基因流动如何影响自然界和进化时间中的物种形成过程。全面解决鞭尾动物的物种形成模式也将揭示与繁殖模式频繁变化相关的过程，这使它们在脊椎动物中独一无二，并有助于它们作为生命和生物医学科学中其他研究领域的模型系统。该奖项反映了美国国家科学基金会的法定使命，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 the basic unit of biological diversity. Scientists must be able to accurately recognize the boundaries between species, and the relationships among them, to understand fundamental biological processes and global patterns of biological diversity. The biology of some organisms makes recognizing species challenging. In particular, when species hybridize in nature it obscures the patterns of morphological and genetic variation that scientists usually use to recognize them. In some cases, hybridization is also associated with unique and interesting biological phenomena, such as changes in reproductive modes, chromosome number, or evolutionary adaptation. In this project, the research team will develop ways to accurately recognize species in a group of lizards where hybridization is common and species identification has been challenging: The North and Central American Whiptail lizards of the genus Aspidoscelis. In addition to improving methods for recognizing species, this research will increase the understanding of the effects of hybridization in the wild, as well as the evolution of reproductive modes in this group of lizards. The research activities will also provide training for a diverse team of scientists and students, many from groups typically underrepresented in science, in Hawaii and California.Whiptails have diversified rapidly and experienced a large amount of introgressive hybridization, which makes them ideal for evaluating phylogenetic and population genetic methods for disentangling hybridization, lineage sorting, and systematic error. Hybridization between gonochoristic species has also repeatedly led to the formation of parthenogenetic lineages at a frequency that is essentially unique to this group. The research team will use genomic and morphological data to disentangle the effects of introgressive hybridization and lineage sorting on the patterns of divergence between all lineages of the Whiptail lizards, and use these results to infer the origins of parthenogenesis across the genus. By examining the geographic, temporal, and genomic dynamics of hybridization and introgression in Whiptails, the project will provide a better understanding of how gene flow impacts the speciation process in nature, and across evolutionary time. Comprehensively resolving patterns of speciation among Whiptails will also shed light on the processes associated with the frequent changes in reproductive mode that make them unique among vertebrates, and contribute to their ability to serve as a model system for other areas of inquiry across the life and biomedical sciences.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.