Anne Lavergne, Anders Gonçalves da Silva, Mathias W. Tobler, Carlos Pedraza, Manuel Ruiz-García, César Paz-y-Miño, Andres Tapia, Benoit de Thoisy, Oswaldo Ramirez, Viviana Quse, Margarita Arana, Association Kwata (Kwata), Kwata, Institut Pasteur de la Guyane, Réseau International des Instituts Pasteur (RIIP), CSIRO Marine and atmospheric research (CSIRO), Commonwealth Scientific and Industrial Research Organisation [Canberra] (CSIRO), Laboratorio de Genética de Poblaciones - Biología Evolutiva, Unidad de Genética, Departamento de Biología, Facultad de Ciencias, Centro tecnologico de recursos amazonicos, Laboratorios de Investigación y Desarrollo (LID), Universidad Peruana Cayetano Heredia (UPCH), Facultad de ciencias veterinarias [Sante Fe] (FCV), Universidad Nacional del Litoral [Santa Fe] (UNL), Instituto de investigaciones biomedicas, Universidad de las Américas, Andes to Amazon Biodiversity Program, Botanical Research Institute of Texas, Laboratorio des Biologia evolutiva de vertebrados, Universidad de los Andes [Bogota] (UNIANDES), and The study was funded by the project SPECIES, funded by WWF Network, European Funds (FEDER), FFEM, the DGIS and the French Ministry of Higher Education and Research andd by the ODEPLAN-UC-PUCE project.
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 largest Neotropical 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 fossil data, 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 in relation 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 the ecological 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 the end 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 regions proposed to define conservation priorities in the Neotropics. This discrepancy sheds doubt into this scheme's ability to generate effective conservation planning for vagile species., The study was funded by the project SPECIES, funded by WWF Network, European Funds (FEDER), FFEM, the DGIS and the French Ministry of Higher Education and Research andd by the ODEPLAN-UC-PUCE project. Argentinean samples were kindly provided by Zoológico de Roque Sáenz Peña; Granja La Esmeralda, and Centro de Rescate de Fauna Autóctona. A. Tapia performed this work to fulfill partial requirements for a M.Sc. degree in Biodiversity in Tropical Areas and its Conservation at the Universidad Internacional Menéndez Pelayo (UIMP, Spain), a Master's Programme funded by the Spanish National Research Council (CSIC, Spain) and carried out at the Universidad Central del Ecuador. We would like to thank Dr. Anna Neuheimer and four anonymous reviewers for providing helpful comments. Finally, we wish to acknowledge the IUCN/SSC Tapir Specialist Group for promoting tapir conservation and creating the forums that allowed this study to flourish.