Phylogenetic relationships of the order insectivora based on complete 12S rRNA sequences from mitochondria

Abstract

Despite numerous studies, there is no single accepted hypothesis of eutherian ordinal relationships. Among the least understood mammalian orders is the group Insectivora. Currently, molecular and morphological data are in conflict over the possible monophyly of the living members of Insectivora (lipotyphlans), and the relationships within the group remain largely unresolved. One of the primary criticisms concerning molecular analyses is the noticeable lack of data from a well-sampled group of lipotyphlan insectivores. The mitochondrial 12S rRNA gene has been widely used to resolve interordinal and intraordinal relationships across a variety of mammalian taxa. This study compares 118 complete mammalian 12S rRNA sequences, representing all of the 18 eutherian orders and 3 metatherian orders, and includes as well taxa from each of the six families of lipotyphlan insectivores. Insectivoran lineages are thought to have diverged concurrently with the general radiation of mammalian orders.