Dissertation Research: Phylogeny of 'Tenrecoid' Insectivorans (Lipotyphla: Mammalia)

9800908只罗斯食虫动物是最古老和最多样化的哺乳动物群体之一。生活在马达加斯加和东非的食虫科哺乳动物是一个特别多样化的群体。这个类群与其他食虫动物的历史(系统发育)关系还不是很清楚。此外，目前还不清楚在北美大陆、加勒比海和亚洲发现的化石和最近发现的类似Tenrec的哺乳动物是否属于Tenresidae，如果是的话，也不清楚是什么因素决定了这些动物过去和现在的分布。一份采样充分的食虫科和其他新近灭绝的食虫动物的系统发育图不仅有望揭示天牛科的分类和生物地理问题，而且还将揭示哺乳动物系统学的更大问题，包括食虫哺乳动物之间的历史关系以及非洲特有哺乳动物的起源和多样性。在这项博士论文研究中，Callum Ross、Ross D.MacPhee和学生Robert J.Asher将收集现存和灭绝的食虫动物骨学的形态数据，以及以前未知的Tenricidae和相关哺乳动物的软组织形态方面的数据。这些数据将与分子序列数据一起使用简约的计算机程序进行分析。将创建用于系统发育分析的明确假设集，这些假设集改变了字符加权的使用、排序、外群的选择以及对具有缺失数据的字符的处理。关于TenreCid系统发育的结论将在一定程度上基于这些假设集产生的树之间的一致性。

9800908 Ross Insectivores, collectively, are among the oldest and most diverse groups of mammals. Living mammals in the insectivore family Tenrecidae, which are found in Madagascar and eastern Africa,is a particularly diverse group. The historical (phylogenetic) relationships of this group to other insectivores are not well known. Moreover, it is not clear whether fossil and recent tenrec-like mammals found in continental North America, the Caribbean, and Asia belong to the Tenrecidae, and if so it is not clear what factors were involved in determining past and present distributions of these animals. A well-sampled phylogeny of tenrecids and other recent and extinct insectivorans promises to shed light not only on questions of the taxonomic and biogeography of the Tenrecidae, but also on larger issues of mammalian phylogeny, including the historical relationships among insectivorous mammals and the origin and diversification of endemic African mammals. In this doctoral dissertation research, Callum Ross, Ross D. MacPhee and student Robert J. Asher will collect morphological data on osteology of living and extinct insectivorans, as well as previously unknown aspects of soft-tissue morphology among Tenricidae and related mammals. These data will be analyzed in tandem with molecular sequence data using parsimony-based computer programs. Explicit assumption sets for phylogenetic analysis will be created that vary the use of character weighting, ordering, the choice of outgroups, and the treatment of characters with missing data. Conclusions regarding tenrecid phylogeny will be based partly on consistencies across trees generated by these assumption sets.