From the cover: Riverine barriers and the geographic distribution of Amazonian species

Claude Gascon, Jay R. Malcolm, James L. Patton, Maria N. F. da Silva, James P. Bogart, Stephen C. Lougheed, Carlos A. Peres, Selvino Neckel, Peter T. Boag

Research output: Contribution to journalArticlepeer-review

220 Citations (Scopus)


Rivers have been suggested to have played an important role in shaping present-day patterns of ecological and genetic variation among Amazonian species and communities. Recent molecular studies have provided mixed support for the hypothesis that large lowland Amazonian rivers have functioned as significant impediments to gene flow among populations of neotropical species. To date, no study has systematically evaluated the impact that riverine barriers might have on structuring whole Amazonian communities. Our analyses of the phylogeography of frogs and small mammals indicate that a putative riverine barrier (the Jurua River) does not relate to present-day patterns of community similarity and species richness. Rather, our results imply a significant impact of the Andean orogenic axis and associated thrust-and-fold low-land dynamics in shaping patterns of biotic diversity along the Jurua. Combined results of this and other studies significantly weaken the postulated role of rivers as major drivers of Amazonian diversification.
Original languageEnglish
Pages (from-to)13672-13677
Number of pages6
JournalProceedings of the National Academy of Sciences
Issue number25
Publication statusPublished - 2000

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