EAPSI: Making Sense of Exceptional Diversity: Coexistence of Many Species in the Mammal Communities

地球上的生命并不是均匀分布的。虽然物种丰富度通常在热带达到顶峰，但生物多样性在全球和地方尺度上都非常广泛。印度尼西亚的热带海洋岛屿苏拉威西岛拥有非常高的生物多样性，但鼠类啮齿动物（大鼠和小鼠）动物群尤其引人注目。一些山地群落包含多达23种共存的鼠类物种，使这些物种成为地球上最丰富的近亲哺乳动物群落。然而，尽管栖息地难以区分，一些山地群落只有10个物种。适应性辐射理论预测，为了共存，群落中的物种不能依赖于相同的资源，而是通过饮食，栖息地或两者的变化来分配资源。为了了解资源是如何分配的，这个合作项目将从维多利亚博物馆哺乳动物馆长Kevin Rowe博士实验室的博物馆标本中生成高分辨率的形态和饮食数据。有了这些数据，这个项目将测试的预测，物种最丰富的社区的成员存在于更大的多样性资源，从更广泛的栖息地比物种较少丰富的社区。 这个项目为国际合作提供了一个难得的机会，同时提供了证据，说明一些群落是如何如此多样化的，这个问题从进化思想的早期就一直困扰着生物学家。适应性辐射理论预测，必须存在足够的生态空间，才能让密切相关的物种共存。计算一个群落所占的生态体积可以解释资源是如何分配的。苏拉威西岛的鼠类（大鼠和小鼠）动物区系非常丰富，一些山地群落包含多达23种共存物种。然而，这种多样性并不是均匀分布在整个岛屿上，一些山地社区只有10个物种。这种变化提供了一个自然的实验，在社区集会的潜力，以阐明这些高度多样化的社区起源和维持。这项合作研究将利用维多利亚博物馆的自然历史藏品来确定整个苏拉威西岛山地社区所填充的生态位体积，测试当地社区生态位体积与物种丰富度呈正相关的预测。生态位体积将使用高分辨率骨骼成像（uCT扫描），饮食的同位素分析和消化道结构的新组合进行量化，提供了苏拉威西啮齿动物如何利用可用资源的综合视图。这个合作项目将决定丰富的群落是否将更多的物种聚集到相同的生态体积中，或者扩大总体积，从而潜在地解决进化生态学中一个长期存在的普遍问题。这个奖项是东亚和太平洋夏季研究所项目下的一个奖项，支持一名美国研究生的夏季研究，由美国国家科学基金会和澳大利亚科学院联合资助。

Life on the planet is not evenly distributed. Though species richness often peaks in the tropics, biological diversity is remarkably wide-ranging at both global and local scales. The tropical oceanic island of Sulawesi, Indonesia contains exceptionally high biodiversity, but the murine rodent (rats and mice) fauna is especially remarkable. Some montane communities containing up to 23 co-occurring murine species, making these the richest communities of closely related mammals on the planet. However, despite indistinguishable habitats, some montane communities contain as few as 10 species. The theory of adaptive radiation predicts that, in order to coexist, species in a community must not rely on the same resource, but instead partition resources through variation in diet, habitat, or both. To understand how resources are partitioned, this collaborative project will generate high-resolution morphological and dietary data from museum specimens in the lab of Dr. Kevin Rowe, Curator of Mammals at Museum Victoria. With these data, this project will test the prediction that members of the most species rich communities are existing on a greater diversity of resources from a wider variety of habitats than the less species rich communities. This project represents an exceptional opportunity for international collaboration while providing evidence that will illuminate how some communities are so diverse, an issue that has puzzled biologists since the earliest days of evolutionary thought.The theory of adaptive radiation predicts that adequate ecological space must exist for closely related species to co-occur. Calculating the ecological volume occupied in a community can explain how resources are partitioned. The murine rodent (rats and mice) fauna of Sulawesi is remarkable, with some montane communities containing up to 23 co-occurring species. However, this diversity is not distributed equally across the island, and some montane communities contain as few as 10 species. This variation provides a natural experiment in community assembly with the potential to illuminate how these hyperdiverse communities originate and are maintained. This collaborative research will use natural history collections at Museum Victoria to determine the ecological niche volume filled by montane communities across Sulawesi, testing the prediction that local community niche volume will be positively correlated with species richness. Niche volume will be quantified using a novel combination of high resolution skeletal imaging (uCT scans), isotopic analyses of diet, and the structure of digestive tracts, providing an integrated view of how Sulawesi rodents exploit available resources. This collaborative project will determine whether rich communities pack more species into the same ecological volume, or expand total volume, potentially resolving a long-standing, general question in evolutionary ecology.This award, under the East Asia and Pacific Summer Institutes program, supports summer research by a U.S. graduate student and is jointly funded by NSF and the Australian Academy of Science.