La dispersión, los ríos y los eventos históricos determinan la genética de la rana amazónica

Título: The interplay of dispersal limitation, rivers, and historical events shapes the genetic structure of an Amazonian frog

Resumen :

Disentangling the impact of landscape features such as rivers and historical events on dispersal is a challenging but necessary task to gain a comprehensive picture of the evolution of diverse biota such as that found in Amazonia. Adenomera andreae, a small, territorial, terrestrial frog species of the Amazonian forest represents a good model for such studies. We combined cytochrome b sequences with 12 microsatellites to investigate the genetic structure at two contrasted spatial scales in French Guiana: along a similar to 6-km transect, to evaluate dispersal ability, and between paired bank populations along a similar to 65-km stretch of the Approuague river, to test the effect of rivers as barriers to dispersal. We observed significant spatial genetic structure between individuals at a remarkably small geographical scale, and conclude that the species has a restricted dispersal ability that is probably tied to its life-history traits. Mitochondrial and microsatellite data also indicate a high level of differentiation among populations on opposite banks of the river, and, in some cases, among populations on the same riverbank. These results suggest that the observed population structure in A. andreae is the result of restricted dispersal abilities combined with the action of rivers and Quaternary population isolation. Given that Amazonia hosts a great portion of anurans, as well as other small vertebrates, that display life-history traits comparable with A. andreae, we argue that our analyses provide new insights into the complex interactions among evolutionary processes shaping Amazonian biodiversity.

Autores : Antoine Fouquet

Direcciones :

1. Departamento de Zoología, Instituto de Biobiencias, Universidad de Sao Paolo (Brasil)

2. Instituto Ciencias del Mar, CSIC, Barcelona (España)

3. Universidad Aix Marsella, Marsella (Francia)

4. Departamento de Biología de la Universidad de Mississippi, Mississipi (EE UU)

5. UMR ECOFOG, INRA, Kourou 97387, Guayana Francesa