Incongruent patterns of morphological, molecular, and karyotypic variation among populations of Ctenomys pearsoni (Rodentia, Ctenomyidae)

Abstract

a b s t r a c tThe genus Ctenomys of subterranean rodents is one of the most diverse of the mammal radiation. In addition to external and skull morphology, studies of Ctenomys alpha taxonomy have relied in an intense manner on chromosomal variation and several populations of this genus have been characterized only by means of cytogenetic techniques.Ctenomys pearsoni is the most karyotypically variable species of the genus (2n =56-70). The goal of this study was to assess the pattern of geographic variation of the skull morphology in several karyomorphs of Ctenomys pearsoni. Our main results indicate that, with the exception of the Solís karyomorph, the remaining are morphologically indistinguishable. These results also agree with previous morphological and population genetics analyses performed in this species. Taken together the available evidence, we support the point of view that not all fixations of chromosomal rearrangement define independent evolutionary units.

Evolutionary history of the Karoo bush rat, Myotomys unisulcatus (Rodentia: Muridae): disconcordance between morphology and genetics

“…Discordance between phenotypic traits and genetic data sets may be driven by elevated molecular lineage diversification, phenotypic plasticity or rapid morphological divergence (Endler, 1980; Bromham et al ., 2002; Wiens et al ., 2006). Because of these differences, morphological similarities may not always reflect the common ancestry of taxa (D'Anatro & D'Elia, 2010). The taxonomy of southern African rodents (especially subspecies and ecotypes) are based mainly on morphological characteristics (De Graaff, 1981) and it is known that body size, for example, can be environmentally influenced (Cardini, Jansson & Elton, 2007).…”