RESUMEN
We use analyses of phylogeographic population structure across a suite of 12 mammalian, avian, amphibian, and reptilian species and species-groups to assess the role of Late Miocene to Pleistocene geological history in the evolution of a distinct Baja California Peninsular Desert biota. Comparative examination of phylogroup distributions provides support for previously hypothesized vicariant events produced by: a middle Pleistocene midpeninsular seaway, a late Pliocene northward transgression of the Sea of Cortéz, and a Pliocene seaway across the southern peninsular Isthmus of La Paz. Most of this phylogeographic architecture is cryptically embedded within widespread taxonomic species and species-groups, such that the unique evolutionary history of the Peninsular Desert has been obscured and ignored. The Peninsular Desert can no longer be considered a subset of the Sonoran Desert-it is a separate regional desert with its own unique evolutionary history, ecological arena, and conservation value.
Asunto(s)
Anfibios/genética , Aves/genética , Evolución Molecular , Reptiles/genética , Roedores/genética , Anfibios/clasificación , Animales , Secuencia de Bases , Aves/clasificación , California , ADN Complementario , ADN Mitocondrial/análisis , ADN Mitocondrial/clasificación , Demografía , Fósiles , México , Datos de Secuencia Molecular , Filogenia , Reptiles/clasificación , Roedores/clasificaciónRESUMEN
Phylogenetic analysis of 699 bp of the mitochondrial DNA (mtDNA) COIII and 450 bp of the cytochrome b genes among 14 species of coarse-haired pocket mice (Heteromyidae: Chaetodipus) corroborated previous indications that genetic divergence between species and species groups within the genus is generally very high, suggesting old times of divergence, and that the nominal species C. baileyi represents a highly divergent lineage within the genus, with no closely related extant sister species. Analysis of phylogeographic structure among 51 individuals from 12 localities throughout the geographic range of C. baileyi revealed three geographically separate mtDNA haplotype lineages. The oldest split separates populations east and west of the Colorado River, a pattern that is congruent with chromosomal and allozyme electrophoretic evidence. We consider the western populations to represent a distinct species, C. rudinoris. Within C. rudinoris, mtDNA haplotypes are further subdivided into northern and southern lineages along the Baja California Peninsula. Comparison of phylogeographic structure in the baileyi species group and the codistributed Peromyscus eremicus species group implies two points of codivergence and thus supports two historical vicariance hypotheses proposed for biotas distributed across the peninsular and continental warm deserts: a late Neogene (3 Ma) northern extension of the Sea of Cortéz and a mid-Pleistocene (1 Ma) midpeninsular seaway across Baja California.
Asunto(s)
Clima Desértico , Peromyscus/genética , Filogenia , Roedores/genética , Animales , Grupo Citocromo b/genética , ADN Mitocondrial/química , ADN Mitocondrial/genética , Complejo IV de Transporte de Electrones/genética , Evolución Molecular , Geografía , Haplotipos , México , Datos de Secuencia Molecular , Peromyscus/clasificación , Roedores/clasificación , Análisis de Secuencia de ADNRESUMEN
El mono dormilon (Aotus) es un importante huesped experimental de la malaria, pero en la actualidad se cuenta con muy pocos ejemplares de ese tipo de simios. Esta escasez obstaculiza las investigaciones para elaborar farmacos y vacunas contra la malaria. Este articulo describe los resultados de la cria de una pequena colonia de monos Aotus que, realizada en gran escala, podria resolver en parte el problema que representa la escasez de esos primates