Phylogeography and ecological niche modeling of the South American cricetid rodent Graomys griseoflavus, with insights into its chromosomal evolution

JOSÉ H. URQUIZO; LUIS IGNACIO FERRO; AGUSTINA MURGIA; ULYSES PARDIÑAS; JUAN JOSÉ MARTÍNEZ

BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2024

0024-4066

The rodent Graomys griseoflavus has a wide geographical distribution in the Arid Diagonal of South America, showing variation in the diploid number (2n= 33 - 38) caused by three different Robertsonian (Rb) translocations. Two contrasting hypotheses have been proposed to explain the origin and evolution of this polymorphism, unique and sequential event, or multiple and independent origin of Rb translocations. Here, we combined phylogeography and ecological niche modeling to elucidate the evolutionary history of G. griseoflavus and aid to contrast these hypotheses. The results indicated a demographic increase that would have begun about 150 ky from High Monte ecoregion. The spatial distributions of these populations were coincident with areas of highest habitat suitability. The paleoclimatic projections suggested the presence of two main glacial refugia, coincident with the main genetic clusters. G. griseoflavus suffered two pulses of southward expansion at about 220 and 210 ky ago. More recently (ca. 20 kya), there was a secondary contact between the southern populations (Low Monte ecoregion) expanded northwards and simultaneously the northern populations (High Monte ecoregion) expanded into marginal areas of the Chaco ecoregion. Our results allow us, together with the cytogenetic evidence, to support the multiple and independent origin of Rb translocations.