Patterns of speciation in two sibling species of Graomys (Rodentia, Cricetidae) based

J. J. MARTÝ´NEZ, R. E. GONZALEZ-ITTIG, G. R. THEILER, R. OJEDA, C. LANZONE, A. OJEDA Y N. GARDENAL

JOURNAL OF ZOOLOGICAL SYSTEMATICS AND EVOLUTIONARY RESEARCH

WILEY-BLACKWELL PUBLISHING, INC

Año: 2010 vol. 48 p. 159 - 166

0947-5745

To increase our understanding of the speciation process occurred in the sibling species Graomys griseoflavus and Graomys centralis, a phylogeographic study was conducted based on sequences of a hypervariable segment of the mtDNA D-loop region. The resulting haplotype phylogenetic network showed two well-defined clusters, one for each species. The clusters were connected by two haplotypes from localities that are almost 300 km apart, one situated in the Monte eco-region and the other, in the Chaco. This result is in agreement with a previous hypothesis about the geographical context in which the cladogenetic process occurred. A divergence time of 0.15–0.28 million years was estimated, which is consistent with a process of recent speciation. An amova test confirmed that at present gene flow between species does not exist. The mismatch distribution analyses suggest that the geographical and demographic expansion undergone by the species is related to the climatic events that occurred in the region during the Quaternary.Graomys griseoflavus and Graomys centralis, a phylogeographic study was conducted based on sequences of a hypervariable segment of the mtDNA D-loop region. The resulting haplotype phylogenetic network showed two well-defined clusters, one for each species. The clusters were connected by two haplotypes from localities that are almost 300 km apart, one situated in the Monte eco-region and the other, in the Chaco. This result is in agreement with a previous hypothesis about the geographical context in which the cladogenetic process occurred. A divergence time of 0.15–0.28 million years was estimated, which is consistent with a process of recent speciation. An amova test confirmed that at present gene flow between species does not exist. The mismatch distribution analyses suggest that the geographical and demographic expansion undergone by the species is related to the climatic events that occurred in the region during the Quaternary.amova test confirmed that at present gene flow between species does not exist. The mismatch distribution analyses suggest that the geographical and demographic expansion undergone by the species is related to the climatic events that occurred in the region during the Quaternary.