DISSERTATION RESEARCH: Harnessing genomics to test the mechanisms causing adaptive phenotypic divergence along elevational gradients in a poison frog.

这个项目调查了沿着山坡的环境条件如何导致不同青蛙种群之间的遗传变化和分歧。确定种群遗传分化并最终成为独立物种的机制对于理解生物多样性的起源非常重要。沿着环境梯度的生态差异可以驱动种群之间的分化。该项目将确定基因负责遗传分歧的性状值之间的人口安东尼？一种分布于厄瓜多尔沿着多个山坡和海拔梯度的箭毒蛙Epipedobates anthonyi。研究人员将测试基因的自然选择，并将这种选择与环境因素联系起来，以确定哪些因素对观察到的分歧负责。这些结果将有助于我们理解为什么热带系统如此多样化，并有助于预测对气候变化的进化反应。此外，该项目还包括本科生培训、教育讲习班和K-12外联活动。该项目利用一个独特的研究系统来调查在没有地理隔离的情况下促进种群分化的驱动因素和机制。花上足螨种群在体型、体色、雄虫广告叫声和耐热性等蛹适应性状上沿海拔梯度表现出沿着的表型差异。尽管这种表型的分歧，中性遗传变异的分析表明，这些人口并不是孤立的。使用基因组方法，研究人员将检查整个基因组的分歧选择的签名，将环境变化与观察到的分歧相关联，并检测可能导致观察到的海拔梯度表型变异的遗传变化。组织样本已收集到35个种群，包括分布在四个重复的海拔梯度的这个物种。这个高度综合性的项目将提供一个深入的分析的相对作用的适应性遗传分化和表型可塑性观察到的模式在自然种群的表型分歧。

This project investigates how environmental conditions along mountainsides leads to genetic change and divergence among different frog populations. Identifying the mechanisms by which populations genetically diverge, and eventually become separate species, is important for understanding the origins of biological diversity. Ecological differences along environmental gradients can drive divergence among populations. This project will identify the genes responsible for genetic divergence of trait values among populations of Anthony?s poison arrow frog, Epipedobates anthonyi, which occurs along multiple mountainsides and elevation gradients in Ecuador. The researchers will test for natural selection on genes and relate that selection to environmental factors so as to determine which are responsible for the observed divergence. The results will contribute to our understanding of why tropical systems are so diverse and help predict evolutionary responses to climate change. In addition, the project includes the training of undergraduates, educational workshops, and K-12 outreach activities. This project takes advantage of a unique study system to investigate the drivers and mechanisms that promote population divergence in the absence of geographic isolation. Populations of Epipedobates anthonyi show phenotypic divergence along elevation gradients in putatively adaptive traits including size, coloration, male advertisement calls, and thermal tolerance. Despite this phenotypic divergence, analyses of neutral genetic variation indicate that these populations are not isolated. Using genomic approaches, the researchers will examine signatures of divergent selection across the genome, correlate environmental variation with the observed divergence, and detect genetic changes likely responsible for observed phenotypic variation across elevation gradients. Tissue samples have been collected from 35 populations that encompass the distribution of this species across four replicated elevational gradients. This highly integrative project will provide an in-depth analysis of the relative roles of adaptive genetic differentiation and phenotypic plasticity on observed patterns of phenotypic divergence in natural populations.