Article
Divergence in Zygodontomys (Rodentia: Sigmodontinae) and Distribution of Amazonian Savannas
Registro en:
BONVICINO, Cibele R. et al. Divergence in Zygodontomys (Rodentia: Sigmodontinae) and Distribution of Amazonian Savannas. Journal of Heredity, v. 100, n. 3, p. 322-328, 2009.
0022-1503
1465-7333
Autor
Bonvicino, Cibele R.
Gonçalves, Pablo R.
Oliveira, João A. de
Oliveira, Luiz Flamarion B. de
Mattevi, Margarete S.
Resumen
Northern South America presents a diverse array of nonforest or savanna-like ecosystems that are patchily distributed. The
distribution of these open habitats has been quite dynamic during Quaternary glacial–interglacial cycles; yet, the relevance of
climatically driven vicariance events to the diversification of nonforest Amazonian vertebrates remains poorly known. We
analyzed karyologic and mitochondrial DNA sequence data of the genus Zygodontomys, a small cricetid rodent distributed
throughout nonforest habitats of northern Amazonia. Samples analyzed represented 4 Brazilian Amazonian localities and 2
French Guiana localities. Karyologic variation among Amazonian Brazilian Zygodontomys populations is high, with, at least,
3 karyomorphotypes. Molecular phylogenetic analyses recovered 3 major clades congruent with known karyotypes, a finding
that suggests the existence of 3 species, 2 of which currently undescribed. The French Guiana and Surumu´ clade, identified
as Zygodontomys brevicauda microtinus, is characterized by 2n 5 86 and is sister to the clade formed by the 2 nondescribed
forms. The Rio Negro–Rio Branco form is characterized by 2n 5 82, and the Ferreira Gomes–Itapoa´ form is characterized
by 2n 5 84. The distribution of the 3 Zygodontomys lineages identified is in accordance with the geography of the open
vegetation patches in Northern Amazonia, and divergence time estimates relate speciation events to themiddle-upper Pleistocene,
supporting the prominent role of Quaternary climatically driven vicariance events in the diversification of the genus. 2030-01-01