DISSERTATION RESEARCH: Endocranial capacity and extinction risk in mammals

在现存的近5400种哺乳动物中，由于栖息地丧失、过度开发、气候变化和其他人为干扰，其中四分之一目前面临灭绝的危险。不被认为有灭绝危险的物种经常被列入受威胁物种名单。在物种数量受到严重威胁之前确定更值得保护的物种，可能比针对已知种群数量下降的物种更有效、更经济地保护哺乳动物多样性。在化石记录中，已经灭绝的哺乳动物的相对大脑大小（大脑与身体大小的比例）明显小于今天仍然存活的物种。此外，目前被列为濒危的食肉动物物种的相对脑容量明显小于没有灭绝威胁的食肉动物物种。基于这些初步数据，本研究项目将更广泛地研究相对脑容量与保护状况之间的关系，以验证相对脑容量较大的物种在面对环境变化时可能更成功，从而更能抵御灭绝的假设。这个项目的独特之处在于，它既研究了现代哺乳动物物种，使用了迄今为止采用的更全面的方法，也研究了过去3000万年的哺乳动物物种。这项研究项目的目标是为科学家、政府和保护组织提供工具，以识别可能濒临灭绝的物种。通过提供一种廉价且易于部署的指标来主动识别受关注的物种，并指导采取行动阻止物种损失，这项工作可以为保护科学和政策提供重要的见解。这项研究将通过出版物、会议发言和与非政府组织的继续通讯来传播。此外，这项工作产生的大量数据集将提供给其他研究人员、州和联邦机构。该研究项目将涉及高中和本科生的研究方法和分析，并支持研究生的博士研究。

Of the nearly 5,400 mammalian species alive today, a quarter of them are currently at risk of extinction due to loss of habitat, overexploitation, climate change and other human disturbances. Species not considered to be at risk of extinction are regularly added to the list of threatened species. Identifying species of greater conservation concern before their populations become critically threatened may be more effective and less expensive for protecting mammalian diversity than targeting species already known to have suffered population declines. In the fossil record, species of mammals that have gone extinct had significantly smaller relative brain sizes, (the size of the brain relative to body size), than species that are still alive today. Further, carnivore species listed currently as endangered have significantly smaller relative brain sizes as compared to carnivore species that are not threatened with extinction. Based on this preliminary data, this research project will examine more broadly the relationship between relative brain size and conservation status in order to test the hypothesis that species with larger relative brain sizes may be more successful in the face of environmental change, and thus more resistant to extinction. This project is unique in that it examines both modern mammalian species, using a more comprehensive methodology than has been employed to date, as well as mammalian species over the last 30 million years. A goal of this research project is to produce tools that scientists, governments and conservation organizations can use to identify species that may be extinction-prone. By providing an inexpensive and readily deployable metric for proactively identifying species of concern, and guiding action to stem species loss, this work could provide important insights for conservation science and policy. This research will be disseminated through publications, conference presentations and continued communication with non-governmental organizations. Additionally, the substantial dataset that results from this work will be made available to other researchers and state and federal agencies. This research project will involved high school and undergraduate students in research methods and analysis, and supports the doctoral research of a graduate student.