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高数量的生物多样性。虽然这其中的原因还不是很清楚，但一些假说试图解释这种高物种形成率；大多数集中在新热带地区研究得很好的生物群。这一研究项目的目标是通过关注马达加斯加，更好地了解热带生物多样性，马达加斯加是进行这项工作的天然实验室。由于与世隔绝，马达加斯加非常适合探索生物如何在零散的栖息地中分化和持续存在，而不会受到迁入或迁出邻近地区的混乱影响。研究人员将研究蚂蚁的物种形成，这些蚂蚁作为一个群体，比岛屿本身更年轻。因此，所有已知的来自马达加斯加的700多种物种都来自于跨洋殖民者，他们在岛上的物种形成和多样化在他们的后代身上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，科学家们将探索马达加斯加蚂蚁多样性的历史和影响因素。马达加斯加的高度多样性，对地方性蚂蚁的全面采样，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在生态位建模、物种界定和推断关系方法方面的最新进展。这些数据还将允许对现有的生物多样性假设进行严格测试，并检查在观察到的分类群模式中是否存在时间和生态上的共性。这将是迄今为止对热带多样性进行的最广泛的评估之一，并将极大地增进对以下方面的了解：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划分不同的物种。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.