Evolutionary history of the genus Sorex (Soricidae, Eulipotyphla) as inferred from multigene data

Abstract

The genus Sorex is one of the most diverse and ecologically successful lineages of the family Soricidae. We present the first multilocus nuclear phylogeny focusing on the nominal subgenus Sorex s.str., which is distributed mainly in the northern Palearctic. The nuclear tree (six exons) provides more resolution than the mitochondrial data ( cytb ) and supports subdivision into eight species groups within Sorex s.str., most of which correspond to those recognized from chromosome data. The European species S. alpinus is consistently placed as the basal lineage in the Palearctic clade, while the next split separates the east‐Tibetan group of striped shrews ( S . aff. cylindricauda , S. bedfordiae , S. excelsus ). Within the remaining species, the following well‐supported clades are identified at the supra‐group level: “araneus” species group+ S. samniticus ; the “caecutiens” group+the “minutus” group, the latter also including S. minutissimus, S. gracillimus and S. thibetanus. S. raddei and S. roboratus represent separate lineages with no close relatives. The fossil‐calibrated molecular clock placed the divergence between Sorex s.str. and Otisorex at the Early/Middle Miocene boundary. Basal radiation of the crown Sorex s.str. was estimated to have occurred in the middle of the Late Miocene. A more than threefold increase in the diversification rate is inferred for the Early Pliocene. Taxonomic implications including potential genus ranks for Sorex s.str. and Otisorex are discussed. S. alpinus is placed in the monotypic subgenus Homalurus . The full species status of S. buchariensis and S. thibetanus and close relationships between S . cf . cansulus and S. caecutiens are confirmed.

Bibliographic Information