Voles and Lemmings - Phylogeny

Phylogeny

The phylogeny of Arvicolinae has been studied using morphological and molecular characters. Markers for the molecular phylogeny of arvicolines included the mitochondrial DNA cytochrome b (cyb) gene and the exon 10 of the growth hormone receptor (ghr) nuclear gene. The comparison of the cyb and ghr phylogenetic results seems to indicate nuclear genes are useful for resolving relationships of recently evolved animals. As compared to mitochondrial genes, nuclear genes display several informative sites in third codon positions that evolve rapidly enough to accumulate synapomorphies, but slow enough to avoid evolutionary noise. Of note, mitochondrial pseudogenes translocated within the nuclear genome complicate the assessment of the mitochondrial DNA orthology, but they can also be used as phylogenetic markers. Sequencing complete mitochondrial genomes of voles may help to distinguish between authentical genes and pseudogenes.

The complementary phylogenetic analysis of morphological and molecular characters suggests that :

• Ellobius, Prometheomys and Lagurus are among the most basal arvicolines ;
• Dicrostonyx, Phenacomys and Arborimus may form a clade ;
• Core arvicolines include three subclades:
  • Lemmini: Synaptomys, Lemmus, Myopus ;
  • Clethrionomyini: Eothenomys, Myodes ;
  • Arvicolini: Arvicola, Chionomys, Stenocranius and Microtus.
• Microtus sensu lato contains Alexandromys, ‘Neodon’, Mynomes, Lasiopodomys, Terricola, and Microtus sensu stricto ;
• Ondatra and Dinaromys positions are uncertain, probably compromised by the convergent evolution of morphological characters.

Some authorities have placed the zokors within the Arvicolinae, but they have been shown to be unrelated.