Sulawesi as the Crossroads of the Southeast Asian Rodent Radiations

0075555莫拉莱斯和鲁达斯早在阿尔弗雷德·拉塞尔·华莱士时代，人们就开始对马来群岛进行观察和绘制地图，形成了生物地理学这门现代生物学学科的开端：研究动物和植物的分布及其分布的原因。然而，也许部分原因是由于华莱士的巨大影响，从那以后，在生物地理学的发源地马来群岛，再也没有进行过进一步的综合生物学研究。有几项研究单独考察了该群岛某些岛屿上的独特动物种类（如昆虫、鸟类、蝙蝠）。相比之下，我们已经开始整合这些不同的研究，并在整个马来群岛，从亚洲大陆到新几内亚和澳大利亚，开始我们自己的研究。这些综合研究的目标是检验建立在该地区生态研究基础上的一般生物地理学假设。我们的工作重点是dna序列衍生的进化关系的研究在一个单一的动物群体：啮齿动物。特别是，我们将集中研究鼠科，这是种类最多的啮齿动物：超过65%的啮齿动物（1326/2021）是鼠科。我们之所以选择这些啮齿动物，是因为它们在整个地区分布广泛，无处不在，因此我们几乎总是确定要研究生物。我们将使用dna序列数据来确定该地区历史生物地理的主要模式。该项目的具体目标是得出该地区鼠型啮齿动物的基于dna序列的系统发育；这些系统发育将被用来检验关于澳大利亚、巴布亚和苏拉威西亚啮齿动物辐射起源的生物地理学假设。最后，这些数据将用于对该地区啮齿动物之间的关系产生更全面和更有力的看法。我们将把重点放在苏拉威西岛，这是我们当前数据集中缺失的一个关键元素。多年来，我们一直在研究该地区的啮齿动物，并从大陆边缘的岛屿以及新几内亚和澳大利亚收集了样本进行分析；然而，苏拉威西岛对区域生物地理分析（因此对整个生物地理）至关重要，因为生态学衍生的动物研究无法将该岛定位在华莱士所阐明的两个大区域中的任何一个区域内。苏拉威西岛的鼠群是该地区乃至世界上最丰富的啮齿动物之一，由至少41种动物组成，其中36种是当地特有的。在这些地方病中，我们发现了该地区主要的穆尔德群体的充分代表，但最重要的是，一个被称为“老地方病”的群体。这类啮齿动物往往是罕见和孤立的，因此构成了进化和生物地理分析的关键因素。发现这些模式将使我们开始了解该地区的动物殖民化是如何进行的，以及是什么机制导致了世界上最丰富的区域哺乳动物生物群之一。

0075555Morales and RuedasObservations and mapping endeavors in the Malay Archipelago dating back to the time of Alfred Russel Wallace formed the beginnings of the modern biological discipline of biogeography: the study of the distributions of animals and plants, and of the causes of those distributions. However, perhaps in part because of the overwhelming influence of Wallace, no further comprehensive biological studies have since been undertaken in the Malay Archipelago, the birthplace of biogeography. A few studies have examined, in isolation, distinct faunal elements (e.g., insects, birds, bats) of certain of the islands of the archipelago. We have, in contrast, begun to integrate these disparate studies and initiate studies of our own across the entire Malay Archipelago, from Mainland Asia to New Guinea and Australia. These integrative studies have as a goal to test the general biogeographic hypotheses founded on ecological studies of the area. Our work focuses on DNA-sequence derived studies of the evolutionary relationships within a single group of animals: the rodents. In particular, we will concentrate on one family of rodents, the Muridae, which is the most speciose: over 65% of all rodent species (1326/2021) are murids. We chose these rodents because these tend to be widespread and ubiquitous throughout the region, thus we are almost invariably assured of study organisms. We will use the DNA-sequence data to determine what the major patterns of historical biogeography are in the area. The specific objectives of the project are to derive DNA-sequence based phylogenies of the area's murid rodents; these phylogenies will be used to test biogeographic hypotheses that have been proposed for the origin of the Australian, Papuan, and Sulawesian rodent radiations. Finally, the data will be used to generate a more comprehensive and robust vision of the relationships among the region's rodents. We will concentrate on Sulawesi as a key missing element in our current data set. We have been studying the region's rodents for some years and have amassed specimens for analysis from islands on the continental margin as well as New Guinea and Australia; however, Sulawesi is of critical importance to regional biogeographic analyses (therefore to biogeography as a whole), as ecologically derived faunal studies are unable to localize the island within either of the two broad regions elucidated by Wallace. Sulawesi's murid rodent fauna, one of the area's and the world's richest, is constituted by at least 41 species, of which 36 are endemic. Of the endemics, ample representation is found of the major murid groups of the area, but most importantly, a group known as the "Old Endemics." Rodents in this group tend to be rare and isolated and as such constitute key elements in evolutionary and biogeographic analyses. Discovering these patterns will enable us to begin to understand how the faunal colonization of the area was undertaken, as well as what mechanisms are responsible for one of the richest regional mammalian biotas in the world.