DISSERTATION RESEARCH: The Genomic Nature of Adaptation in Anolis lizards

地球上的大多数生物多样性被认为是适应性辐射的结果，这是一种进化现象，许多新物种通过殖民和适应新环境而迅速形成。许多研究人员在过去50年的工作使人们对与适应性辐射相关的大范围进化模式有了新的理解。尽管取得了这些进展，但我们对适应性辐射过程中发生的遗传过程知之甚少。例如，还不知道新的突变在多大程度上只在一个环境中受到独特的青睐，而不是对生活在不同栖息地的多个物种有利。这项建议使用了适应辐射最具代表性的例子之一--西印度群岛的Anolis蜥蜴，解决了我们知识中的这一差距。这项研究将集中在两种栖息在树干上的Anolis物种--一种生活在炎热干燥的环境中，另一种生活在潮湿凉爽的森林中。在多米尼加共和国的一小块地区，这些不同的栖息地紧邻在一起。在这里，这两个物种进行杂交，形成杂交后代。这些独特的环境提供了一个机会来确定哪些基因变异与适应这两个不同环境有关，以及哪些变异对两个物种都有利。为了解决Anolis蜥蜴适应的基因组性质，合作研究人员将使用下一代测序技术来收集每个物种以及杂交物种个体的转录组数据。从测序中获得的基因类型将被用于进行基因组临床分析，以识别在杂交后代中代表过高和代表不足的亲本等位基因。基因组临床分析的结果将与种群基因组分析相结合，以确定全球和局部适应的频率，并首次深入了解与适应辐射相关的微进化过程。

Most of the biological diversity on Earth is thought to result from adaptive radiation, an evolutionary phenomenon where many new species are rapidly formed through colonization of and adaptation to new environments. The work of many researchers over the last fifty years has resulted in an emerging understanding of the broad-scale evolutionary patterns associated with adaptive radiation. Despite these advances, we have little understanding of the genetic processes that take place during adaptive radiation. For instance, it is not known how often new mutations are uniquely favored in one environment alone versus being beneficial to multiple species living in different habitats. This proposal addresses this gap in our knowledge using one of the most iconic examples of adaptive radiation, Anolis lizards from the West Indies. This research will focus on two Anolis species that reside on tree trunks?one living in a hot, dry environment, the other in a moist, cool forest. In a small area of the Dominican Republic, these different habitats are immediately adjacent to one another. Here, the two species interbreed and form hybrid offspring. These unique circumstances provide an opportunity to identify what gene variants are associated with adaptation to the two distinct environments and what variants are beneficial to both species.To address the genomic nature of adaptation in Anolis lizards, the co-investigators will use next-generation sequencing technologies to collect transcriptome data from individuals of each species as well as hybrids. The genotypes derived from this sequencing will be used to perform genomic cline analyses, which identify parental alleles that are over- and underrepresented among hybrids. The results of genomic cline analyses will be combined with population genomic analyses to identify the frequency of global and local adaptations and provide a first insight into the microevolutionary processes associated with adaptive radiation.