NSFDEB-NERC Origins and expansion of endemic biodiversity in western Melanesia and their relation to tectonic evolution

西美拉尼西亚——包括新几内亚——位于亚洲和澳大利亚的交汇处，是地球上最有趣、最令人费解、最未被充分研究的高度多样化地区之一。弄清楚在过去的几百万年里，构造运动是如何将不同的美拉尼西亚地貌分离或结合在一起的，是理解这种生物多样性起源的关键。该项目的目的是阐明构成美拉尼西亚西部大部分地区的五种主要地质地貌的多样性和进化史如何影响该地区生物群的进化，并确定那些在新几内亚、澳大利亚和/或亚洲岛屿地区殖民和辐射的谱系起源中至关重要的古老岛屿陆地。为了实现这一目标，我们将在横跨美拉尼西亚西部五个主要大陆的众多爬行动物和两栖动物（爬虫动物）谱系上构建有日期的系统发育树，这些谱系具有不同的扩散能力、起源时间和自然历史。我们将使用恢复的日期和关系来确定每个分支的起源区域和时间，并追踪它们向新区域的扩展。这些结果与最新的地质模型之间的交叉验证将阐明推动该地区物种形成和扩散的构造事件。我们使用爬虫动物群来解决这些问题，因为它们具有可变但适度的跨海洋传播能力，这使得它们比具有更大（如鸟类）或更小（如陆地蜗牛）传播能力的分类群更好地跟踪地质历史。这项研究将有助于取代过时的、单向的“新几内亚之外”的太平洋生物多样性起源模型，以一种更动态、更细致的理解，即美拉尼西亚古老的、但未得到充分重视的陆地地区长期以来在塑造更广泛地区的生物进化中起着重要作用。

Western Melanesia-including New Guinea-sits at the crossroads of Asia and Australia and is one of the most interesting, puzzling, and understudied hyperdiverse regions on Earth. Clarifying how tectonic movements have sundered or joined different Melanesian landforms in the past several million years is key to understanding the origins of this biotic diversity. The intent of this project is to elucidate how the diversity and evolutionary history of the five major geological landforms that comprise most of western Melanesia have impacted evolution of that region's biota and to identify those ancient insular landmasses critical in the origin of lineages that colonised and radiated across New Guinea, Australia, and/or insular Asia. To meet this goal, we will construct dated phylogenetic trees on a multitude of reptile and amphibian (herpetofauna) lineages having different dispersal abilities, times of origin, and natural histories that span the five major landmasses of western Melanesia. We will use the dates and relationships recovered to identify areas and times of origin for each clade and trace their expansion to new regions. Cross-validation between these results and updated geological models will illuminate tectonic events that drove speciation and dispersal in the region. We use herpetofauna to address these questions because their variable but moderate trans-marine dispersal abilities allow them to better track geological history than do taxa having much greater (e.g., birds) or lesser (e.g., land snails) dispersal capabilities. This research will help to replace the outdated, unidirectional "out-of-New-Guinea" model for origins of Pacific biodiversity with a more dynamic and nuanced understanding that ancient, yet under-appreciated, land areas in Melanesia have long been important in shaping biotic evolution in the broader region.