On the phylogenetic position of a rare Iberian endemic mammal, the Pyrenean desman ( Galemys pyrenaicus)

Abstract

The nucleotide sequences of the complete mitochondrial genome and nine partial nuclear genes of the Pyrenean desman ( Galemys pyrenaicus) were determined in order to establish the relative phylogenetic position of this species at different taxonomic levels within the placental tree. Phylogenetic relationships of desman within the family Talpidae were inferred based on complete mitochondrial cytochrome b gene nucleotide sequence data. The Pyrenean desman was unambiguously recovered as sister group of the Russian desman ( Desmana moschata) confirming the monophyly of the subfamily Desmaninae. However, phylogenetic relationships among major lineages within the Talpidae could not be confidently resolved. Phylogenetic analyses based on mitochondrial (at the amino acid level) and nuclear (at the nucleotide level) sequence data sets confidently placed desman within the Eulipotyphla (that also included moles, shrews, and hedgehogs), and partially recovered placental interordinal relationships. The monophyly of Laurasiatheria (including Eulipotyphla, Chiroptera, Carnivora, Pholidota, Perissodactyla, and Cetartiodactyla) was strongly supported. Mitochondrial amino acid sequences of Pholidota (pangolins) were found to bias phylogenetic inferences due to long-branch attraction effects. A Bayesian inference based on a combined mitochondrial and nuclear data set without Pholidota arrived at an almost fully resolved tree that supported the basal position of Eulipotyphla within Laurasiatheria.