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边界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具有挑战性。特别是，当物种在自然界中杂交时，它掩盖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、染色体数量或进化适应的变化。在这个项目中，研究团队将开发出准确识别一组蜥蜴物种的方法，在这些蜥蜴群体中，杂交很常见，物种识别一直很困难：属于螺旋藻属的北美和中美洲鞭尾蜥蜴。除了改进物种识别方法外，这项研究还将增加对野生杂交效果的了解，以及这群蜥蜴繁殖模式的进化。研究活动还将为夏威夷和加利福尼亚州的不同科学家和学生团队提供培训，其中许多人来自科学界通常代表性较低的群体。惠普塔鱼迅速多样化，经历了大量的渐进式杂交，这使它们成为评估解缠杂交、谱系分类和系统误差的系统发育和种群遗传学方法的理想选择。雌雄异体物种之间的杂交也反复导致孤雌生殖谱系的形成，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数据来解开渐进杂交和谱系排序对惠普尾蜥蜴所有谱系之间分化模式的影响，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Whitails杂交和导入的地理、时间和基因组动力学，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的物种形成过程。全面解决Whitails的物种形成模式也将揭示与繁殖模式的频繁变化相关的过程，使它们在脊椎动物中独一无二，并有助于它们成为生命和生物医学科学中其他研究领域的模式系统。这一奖项反映了NSF的法定使命，并通过使用基金会的智力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.