Collaborative Research: Phylogeography in Madagascar - Using ants to test hypotheses of biotic diversification in a model continent

世界热带地区拥有世界上不成比例的大量生物多样性。尽管其原因尚不清楚，但许多假说试图解释这些高物种形成率；大部分集中在研究得很好的新热带生物群上。这个研究项目的目标是通过关注马达加斯加来更好地了解热带地区的生物多样性，马达加斯加是开展这类工作的天然实验室。由于与世隔绝，马达加斯加非常适合探索生物如何在分散的栖息地中分化和持续存在，而不会受到邻近地区迁移的混淆影响。研究人员将研究蚂蚁的物种形成，作为一个群体，它们比岛屿本身更年轻。因此，在马达加斯加已知的所有700多个物种都来自越洋殖民者，他们在岛上的物种形成和多样化在其后代中留下了这些过程的遗传特征。通过使用分子数据和基因组方法，科学家们将探索影响马达加斯加蚂蚁多样化的历史和因素。马达加斯加的高度多样性，对特有蚂蚁的全面采样，以及新开发的低成本DNA测序技术的可用性，将使这项研究能够测试生态位建模、划分物种和推断关系方法的最新进展。这些数据还将允许对现有的生物多样化假设进行严格测试，并检查在分类群中观察到的模式中是否存在时间和生态共性。这将是迄今为止对热带多样性最广泛的评估之一，并将大大提高对以下方面的理解：1)马达加斯加的生物历史；2)景观特征和环境变化对生物多样性的作用；3)建模方法在多大程度上有助于不同物种的划分。该项目将培养研究生和本科生。

The tropical regions of the world house a disproportionately high amount of the world's biodiversity. Though the reasons for this are not well understood, a number of hypotheses have sought to explain these high rates of speciation; most focusing on the well-studied biota of the Neotropics. The goal of this research project is to better understand biotic diversification in the tropics by focusing on Madagascar, a natural laboratory for such work. Due to its isolation, Madagascar is well suited to explore how organisms diverge and persist in fragmented habitats without the confounding influence of migration to or from adjacent areas. The researchers will study speciation of ants, which as a group, are younger than the island itself. Thus all 700+ species known from Madagascar are derived from transoceanic colonists, whose speciation and diversification on the island has left a genetic signature of these processes in their descendants. By employing molecular data and genomic methods the scientists will explore the history and the factors influencing the diversification of Malagasy ants.This high diversity in Madagascar, the comprehensive sampling of the endemic ants, and the availability of newly developed, low-cost DNA sequencing technologies will allow this study to test recent advances in methods of ecological niche modeling, delimiting species, and inferring relationships. These data also will allow rigorous testing of existing hypotheses of biotic diversification and examination of whether temporal and ecological commonalities exist in patterns observed among taxa. This will be one of the broadest assessments of tropical diversification to date and will greatly enhance understanding of 1) the biological history of Madagascar, 2) the role of landscape features and environmental change on biological diversification, and 3) the extent to which modeling methods can contribute to the delimitation of distinct species. The project will train graduate and undergraduate students.