Tapir

de Thoisy et al. BMC Evolutionary Biology 2010, 10:278 http://www.biomedcentral.com/1471-2148/10/278

RESEARCH ARTICLE

Open Access

Population history, phylogeography, and conservation genetics of the last Neotropical mega-herbivore, the lowland tapir (Tapirus terrestris)
Benoit de Thoisy1,2*, Anders Gonçalves da Silva3, Manuel Ruiz-García4, Andrés Tapia5,6, Oswaldo Ramirez7, MargaritaArana7, Viviana Quse8, César Paz-y-Miño9, Mathias Tobler10, Carlos Pedraza11, Anne Lavergne2

Abstract
Background: Understanding the forces that shaped Neotropical diversity is central issue to explain tropical biodiversity and inform conservation action; yet few studies have examined large, widespread species. Lowland tapir (Tapirus terrrestris, Perissodactyla, Tapiridae) is the largestNeotropical herbivore whose ancestors arrived in South America during the Great American Biotic Interchange. A Pleistocene diversification is inferred for the genus Tapirus from the fossil record, but only two species survived the Pleistocene megafauna extinction. Here, we investigate the history of lowland tapir as revealed by variation at the mitochondrial gene Cytochrome b, compare it to the fossildata, and explore mechanisms that could have shaped the observed structure of current populations. Results: Separate methodological approaches found mutually exclusive divergence times for lowland tapir, either in the late or in the early Pleistocene, although a late Pleistocene divergence is more in tune with the fossil record. Bayesian analysis favored mountain tapir (T. pinchaque) paraphyly inrelation to lowland tapir over reciprocal monophyly, corroborating the inferences from the fossil data these species are sister taxa. A coalescent-based analysis rejected a null hypothesis of allopatric divergence, suggesting a complex history. Based on the geographic distribution of haplotypes we propose (i) a central role for western Amazonia in tapir diversification, with a key role of theecological gradient along the transition between Andean subcloud forests and Amazon lowland forest, and (ii) that the Amazon river acted as an barrier to gene flow. Finally, the branching patterns and estimates based on nucleotide diversity indicate a population expansion after the Last Glacial Maximum. Conclusions: This study is the first examining lowland tapir phylogeography. Climatic events at theend of the Pleistocene, parapatric speciation, divergence along the Andean foothill, and role of the Amazon river, have similarly shaped the history of other taxa. Nevertheless further work with additional samples and loci is needed to improve our initial assessment. From a conservation perspective, we did not find a correspondence between genetic structure in lowland tapir and ecogeographic regionsproposed to define conservation priorities in the Neotropics. This discrepancy sheds doubt into this scheme’s ability to generate effective conservation planning for vagile species.

* Correspondence: benoit@kwata.net 1 Association Kwata, BP 672, 97335 Cayenne cedex, French Guiana Full list of author information is available at the end of the article
© 2010 de Thoisy et al; licensee BioMedCentral Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

de Thoisy et al. BMC Evolutionary Biology 2010, 10:278 http://www.biomedcentral.com/1471-2148/10/278

Page 2of 16

Background A central debate in Neotropical biogeography concerns the importance of Pleistocene climatic and geological events in generating current species richness [1-4]. Molecular evidence across several taxa supports a scenario where most of the observed divergence and speciation events occurred prior to the Pleistocene [5], and are associated with paleogeographic events of the late...