Dissertation Research: Understanding introgression dynamics through a comparative and genome-wide analysis of a tropical suture zone

了解物种形成的过程是生物学中一项长期存在的令人兴奋的挑战。二次接触区，或先前孤立的谱系相遇和互动的区域，是检验关于物种形成的假设和理论的一种方法。本研究调查了澳大利亚热带雨林中一个独特的系统，其中有20多个重叠的次级接触区。这项研究考虑了一个密切相关的蜥蜴群中的四个这样的接触，以调查整个区域的基因渗入模式或基因交换。特别地，本研究探讨了进化力量，如人口过程和选择，如何影响渗入，更一般地说，物种之间的障碍的进化。为了验证这些预测，将使用高通量测序来开发基因组资源，并将使用接触区种群的精细采样和基因分型来测量遗传渗入率。这项研究将作为一个很好的工具，与学生接触，并开展外展活动。美国和澳大利亚的本科生将开发与本项目相关的独立实验室和实地项目。此外，这项研究将通过外展计划与服务不足的中学生和社区大学生分享。最后，这项研究将产生新的基因组和生物信息学工具，供更大的研究界使用。

Understanding how speciation happens is a long-standing and exciting challenge in biology. Zones of secondary contact, or areas where previously-isolated lineages meet and interact, are one way to test hypotheses and theories about speciation. This study investigates a unique system in the Australian rainforest, in which there are over twenty overlapping zones of secondary contact. This study considers four such contacts within a closely-related group of lizards to investigate patterns of introgression, or gene exchange, across the zone. In particular, this study examines how evolutionary forces, such as demographic processes and selection, influence introgression, and more generally, the evolution of barriers between species. To test these predictions, high-throughput sequencing will be used to develop genomic resources, and fine-scale sampling and genotyping of populations in the contact zone will be used to measure rates of introgression.This research will serve as an excellent vehicle to engage with students and to conduct outreach activities. Undergraduate students in both the United States and Australia will develop their own independent laboratory and field projects related to this project. Additionally, this research will be shared with underserved middle school and community college students through outreach programs. Finally, this research will generate new genomic and bioinformatic tools for use by the greater research community.