INVESTIGADORES
PARDIÑAS ulises francisco J.
artículos
Título:
Systematics of Necromys (Rodentia, Cricetidae, Sigmodontinae): species limits and groups, with comments on historical biogeography
Autor/es:
D'ELÍA, G.; PARDIÑAS, U.F.J.; JAYAT, P.; SALAZAR-BRAVO, J.
Revista:
JOURNAL OF MAMMALOGY
Referencias:
Año: 2008 vol. 89 p. 778 - 790
ISSN:
0022-2372
Resumen:
We present the most comprehensive systematic study to date of Necromys, a rodent genus distributed in open
areas north and south of Amazonia and in Andean grasslands. The study is based on sequences of the
cytochrome-b gene that were analyzed by parsimony and Bayesian approaches. The analyses include sequences
of 62 specimens from 51 localities from Argentina, Bolivia, Brazil, Colombia, Paraguay, Peru, Uruguay, and
Venezuela, representing all but 1 of the species currently recognized in the genus. Necromys was recovered as
a monophyletic group and we found a large polytomy at its base that involves 3 lineages. One, represented by the
Andean N. lactens, shows a marked phylogeographic pattern. The 2nd clade is formed by N. urichi from the
northern grasslands of South America and N. amoenus from the central Andes. Results suggest that each of these
taxa may represent more than 1 biological species. The 3rd clade is formed by lowland species found south of
Amazonia. Within this clade N. obscurus is sister to the remaining species. Haplotypes recovered from specimens
assigned to N. benefactus, N. temchuki, and N. lasiurus form a clade, but these taxa do not form reciprocally
monophyletic groups, nor does this large clade possess geographic structure. These genealogical results,
discussed in the context of genetic variation, are the basis of taxonomic (e.g., N. benefactus and N. temchuki are
regarded as junior synonyms of N. lasiurus) and biogeographic considerations.Necromys, a rodent genus distributed in open
areas north and south of Amazonia and in Andean grasslands. The study is based on sequences of the
cytochrome-b gene that were analyzed by parsimony and Bayesian approaches. The analyses include sequences
of 62 specimens from 51 localities from Argentina, Bolivia, Brazil, Colombia, Paraguay, Peru, Uruguay, and
Venezuela, representing all but 1 of the species currently recognized in the genus. Necromys was recovered as
a monophyletic group and we found a large polytomy at its base that involves 3 lineages. One, represented by the
Andean N. lactens, shows a marked phylogeographic pattern. The 2nd clade is formed by N. urichi from the
northern grasslands of South America and N. amoenus from the central Andes. Results suggest that each of these
taxa may represent more than 1 biological species. The 3rd clade is formed by lowland species found south of
Amazonia. Within this clade N. obscurus is sister to the remaining species. Haplotypes recovered from specimens
assigned to N. benefactus, N. temchuki, and N. lasiurus form a clade, but these taxa do not form reciprocally
monophyletic groups, nor does this large clade possess geographic structure. These genealogical results,
discussed in the context of genetic variation, are the basis of taxonomic (e.g., N. benefactus and N. temchuki are
regarded as junior synonyms of N. lasiurus) and biogeographic considerations.b gene that were analyzed by parsimony and Bayesian approaches. The analyses include sequences
of 62 specimens from 51 localities from Argentina, Bolivia, Brazil, Colombia, Paraguay, Peru, Uruguay, and
Venezuela, representing all but 1 of the species currently recognized in the genus. Necromys was recovered as
a monophyletic group and we found a large polytomy at its base that involves 3 lineages. One, represented by the
Andean N. lactens, shows a marked phylogeographic pattern. The 2nd clade is formed by N. urichi from the
northern grasslands of South America and N. amoenus from the central Andes. Results suggest that each of these
taxa may represent more than 1 biological species. The 3rd clade is formed by lowland species found south of
Amazonia. Within this clade N. obscurus is sister to the remaining species. Haplotypes recovered from specimens
assigned to N. benefactus, N. temchuki, and N. lasiurus form a clade, but these taxa do not form reciprocally
monophyletic groups, nor does this large clade possess geographic structure. These genealogical results,
discussed in the context of genetic variation, are the basis of taxonomic (e.g., N. benefactus and N. temchuki are
regarded as junior synonyms of N. lasiurus) and biogeographic considerations.Necromys was recovered as
a monophyletic group and we found a large polytomy at its base that involves 3 lineages. One, represented by the
Andean N. lactens, shows a marked phylogeographic pattern. The 2nd clade is formed by N. urichi from the
northern grasslands of South America and N. amoenus from the central Andes. Results suggest that each of these
taxa may represent more than 1 biological species. The 3rd clade is formed by lowland species found south of
Amazonia. Within this clade N. obscurus is sister to the remaining species. Haplotypes recovered from specimens
assigned to N. benefactus, N. temchuki, and N. lasiurus form a clade, but these taxa do not form reciprocally
monophyletic groups, nor does this large clade possess geographic structure. These genealogical results,
discussed in the context of genetic variation, are the basis of taxonomic (e.g., N. benefactus and N. temchuki are
regarded as junior synonyms of N. lasiurus) and biogeographic considerations.N. lactens, shows a marked phylogeographic pattern. The 2nd clade is formed by N. urichi from the
northern grasslands of South America and N. amoenus from the central Andes. Results suggest that each of these
taxa may represent more than 1 biological species. The 3rd clade is formed by lowland species found south of
Amazonia. Within this clade N. obscurus is sister to the remaining species. Haplotypes recovered from specimens
assigned to N. benefactus, N. temchuki, and N. lasiurus form a clade, but these taxa do not form reciprocally
monophyletic groups, nor does this large clade possess geographic structure. These genealogical results,
discussed in the context of genetic variation, are the basis of taxonomic (e.g., N. benefactus and N. temchuki are
regarded as junior synonyms of N. lasiurus) and biogeographic considerations.N. amoenus from the central Andes. Results suggest that each of these
taxa may represent more than 1 biological species. The 3rd clade is formed by lowland species found south of
Amazonia. Within this clade N. obscurus is sister to the remaining species. Haplotypes recovered from specimens
assigned to N. benefactus, N. temchuki, and N. lasiurus form a clade, but these taxa do not form reciprocally
monophyletic groups, nor does this large clade possess geographic structure. These genealogical results,
discussed in the context of genetic variation, are the basis of taxonomic (e.g., N. benefactus and N. temchuki are
regarded as junior synonyms of N. lasiurus) and biogeographic considerations.N. obscurus is sister to the remaining species. Haplotypes recovered from specimens
assigned to N. benefactus, N. temchuki, and N. lasiurus form a clade, but these taxa do not form reciprocally
monophyletic groups, nor does this large clade possess geographic structure. These genealogical results,
discussed in the context of genetic variation, are the basis of taxonomic (e.g., N. benefactus and N. temchuki are
regarded as junior synonyms of N. lasiurus) and biogeographic considerations.N. benefactus, N. temchuki, and N. lasiurus form a clade, but these taxa do not form reciprocally
monophyletic groups, nor does this large clade possess geographic structure. These genealogical results,
discussed in the context of genetic variation, are the basis of taxonomic (e.g., N. benefactus and N. temchuki are
regarded as junior synonyms of N. lasiurus) and biogeographic considerations.N. benefactus and N. temchuki are
regarded as junior synonyms of N. lasiurus) and biogeographic considerations.N. lasiurus) and biogeographic considerations.