DISSERTATION RESEARCH: Testing the Parallel Speciation Hypothesis in Scincid Lizards of the Eumeces skiltonianus Species Complex

康涅狄格大学的伊丽莎白·乔科什博士和乔纳森·里士满先生获得了一项拨款，用于研究环境条件的差异如何促进新物种的形成(又名。生态物种形成)。这项研究的重点生物是一组密切相关且地理上分布广泛的北美蜥蜴物种，称为石龙鱼。在这一组中，出现了两种不同的形式，它们生活在不同的环境(即生态型)中：在温暖、干旱的生境中，出现了大型单色型；在较凉爽、潮湿的地区，出现了小型条纹型。结合DNA证据表明，大体形式已经独立起源了三次，体型和栖息地关联之间的相关性表明，群体成员之间的进化差异是对不同环境的生理适应的结果。很可能是由于这些身体形态的变化，不同的生态型在繁殖上是不相容的，并且已经分化成单独的进化谱系，可能代表了未被描述的物种。该项目将结合使用DNA数据的分子研究、使用活体动物进行的性隔离行为分析，以及检查内部和外部解剖学的进化变化的发育研究，详细研究这种过程如何在自然种群中发生。虽然这个项目的重点是斯基克，但它将作为研究生态物种形成的一般理论预测的一个模型系统。它还将有助于确定可能对维持和促进生物多样性至关重要的环境特征，并强调使用进化观点认识未描述物种的重要性。此外，这项研究的多学科方法将为研究生提供几个生物生物学领域的培训，并将本科生包括在内，作为实地考察和行为研究的组成部分。最后，所有标本、组织和DNA数据都将公开，以供进一步的科学使用。

A grant has been awarded to Dr. Elizabeth Jockusch and Mr. Jonathan Richmond at the University of Connecticut to investigate how differences in environmental conditions facilitate the formation of new species (a.k.a. ecological speciation). The focal organisms in this study are a group of closely related and geographically widespread North American lizard species known as skinks. Within this group, two distinct forms that inhabit different environments (i.e. ecotypes) occur: a large-bodied, monochrome form in warm, arid habitats and a small-bodied, striped form in cooler, moister areas. In conjunction with DNA evidence indicating that the large-bodied form has originated three times independently, the correlation between body types and habitat association suggests that evolutionary divergence among members of the group is the result of physiological adaptation to alternative environments. Likely as a result of these changes in body morphology, the different ecotypes are reproductively incompatible and have diverged into separate evolutionary lineages that likely represent undescribed species. This project will examine in detail how such processes can occur in natural populations by combining molecular studies using DNA data, behavioral assays of sexual isolation using live animals, and developmental studies that examine evolutionary changes in internal and external anatomy. Although focused on skinks, this project will serve as a model system for studying the general theoretical predictions of ecological speciation. It will also help identify features of the environment that may be critical for maintaining and promoting biological diversity, and highlight the importance of using an evolutionary perspective in recognizing undescribed species. Furthermore, the multidisciplinary approach of the study will provide a graduate student with training in several fields of organismal biology and will include undergraduates as an integral part of the fieldwork and behavioral studies. Lastly, all specimens, tissues, and DNA data will be made publicly available for further scientific use.