Traçando o impacto da elevação dos Andes sobre a evolução de planta neotrópica

sábado, maio 23, 2009

Tracing the impact of the Andean uplift on Neotropical plant evolution

Alexandre Antonellia,1,2, Johan A. A. Nylanderb, Claes Perssona and Isabel Sanmartínc,2

+Author Affiliations

aDepartment of Plant and Environmental Sciences, University of Gothenburg, Box 461, 405 30 Gothenburg, Sweden;

bDepartment of Botany, Stockholm University, 106591 Stockholm, Sweden; and

cDepartment of Biodiversity and Conservation, Real Jardín Botánico, Consejo Superior de Investigaciones Cientificas, Plaza de Murillo 2, 28014 Madrid, Spain

Edited by Bruce H. Tiffney, University of California, and accepted by the Editorial Board April 13, 2009 (received for review November 11, 2008)

Abstract

Recent phylogenetic studies have revealed the major role played by the uplift of the Andes in the extraordinary diversification of the Neotropical flora. These studies, however, have typically considered the Andean uplift as a single, time-limited event fostering the evolution of highland elements. This contrasts with geological reconstructions indicating that the uplift occurred in discrete periods from west to east and that it affected different regions at different times. We introduce an approach for integrating Andean tectonics with biogeographic reconstructions of Neotropical plants, using the coffee family (Rubiaceae) as a model group. The distribution of this family spans highland and montane habitats as well as tropical lowlands of Central and South America, thus offering a unique opportunity to study the influence of the Andean uplift on the entire Neotropical flora. Our results suggest that the Rubiaceae originated in the Paleotropics and used the boreotropical connection to reach South America. The biogeographic patterns found corroborate the existence of a long-lasting dispersal barrier between the Northern and Central Andes, the “Western Andean Portal.” The uplift of the Eastern Cordillera ended this barrier, allowing dispersal of boreotropical lineages to the South, but gave rise to a huge wetland system (“Lake Pebas”) in western Amazonia that prevented in situ speciation and floristic dispersal between the Andes and Amazonia for at least 6 million years. Here, we provide evidence of these events in plants.

biogeography Neotropical biodiversity Rubiaceae

Footnotes

2To whom correspondence may be addressed. E-mail: isanmartin@rjb.csic.es or alexandre.antonelli@systbot.uzh.ch

Author contributions: A.A. and I.S. designed research; A.A. and C.P. performed research; J.A.A.N. and I.S. contributed new reagents/analytic tools; A.A., J.A.A.N., and I.S. analyzed data; and A.A. and I.S. wrote the paper.

↵1Present address: Institute of Systematic Botany, University of Zurich, Zollikerstrasse 107,CH 8008, Zurich, Switzerland.

The authors declare no conflict of interest.

This article is a PNAS Direct Submission. B.H.T. is a guest editor invited by the Editorial Board.

Freely available online through the PNAS open access option.

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