Systematics of Lipotyphlan Insectivores, An Early Lineage of Placental Mammals

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9629319 ALLARD The insectivores in the order Lipotyphla (shrews, moles, hedgehogs and their relatives) represent one of the largest orders of living mammals. However, the genealogical (phylogenetic) relationships among these insectivores, and between Lipotyphla and other groups of mammals, remain poorly understood. Several different and competing explanations for how these animals are related to each other have been suggested. Insectivores are among the first mammals to appear in the fossil record, suggesting that the various lineages of insectivores diverged early in the history of the group (and of mammals in general). It is more difficult to reliably reconstruct the phylogenetic relationships of ancient groups of organisms than of more recent ones. In this study, Marc C. Allard will use a multidisciplinary approach to investigate the problem of robustly reconstructing the phylogeny of Lipotyphla. Allard will obtain sequence information from mitochondrial and nuclear genes found in representatives of all families of insectivores. The sequences will be compared with each other and with sequences from other mammalian groups, and will be used to construct phylogenetic trees. The gene sequences will be analyzed individually and in combination; also, data from published morphological and anatomical information will be encoded, included in a single data matrix with the gene sequence data, and used in phylogenetic reconstructions. The results should provide fundamental information on the early history and present-day relationships of mammals.