Jorge Perez
Ph.D. Student
Ecology, Systematics and Evolution
Department of Biology
University of Missouri-St. Louis
Photo: Shannon Hackett
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Education:
- B.Sc. in Biology (Cum Laude), 1990. Universidad Simon Bolivar, Caracas, Venezuela.
M.Sc. in Biology, 1996. University of Missouri-St. Louis, U.S.A.
Research Interests:
- Molecular Phylogenetics, Biogeography, Ecology.
Current Research:
- For my doctorate at the University of Missouri, St. Louis, I am studying the molecular systematics of Myioborus, a genus of warblers called Redstarts. The phylogeny I generate will be used to discuss species limits, taxonomy, and historical biogeography in the genus. Historical biogeography focuses on the reconstruction of the geographic patterns of distribution of populations and species and provides insight into the evolutionary history of species and communities.
The avifauna of South America is the most diverse of any continent and shows a high degree of regional endemism. The highland mountains of my native Venezuela (tepuis) are considered an important region of endemism, known as the Pantepui region. The presence of many common elements between montane Andean and Pantepuian avifaunas has been the core element used to propose that the Pantepuian avifauna has been the result of continuous dispersal from the Andes, ignoring the possibility that some Andean montane lineages could have originated in the geologically much more ancient Pantepui region. Moreover, following this argument, birds from different tepui mountains might have been the result of separate colonization events, or the Pantepui region resulted in an important diversification region for the bird fauna in ancient times. Clades that are widely distributed in the Andes and have their most primitive sister group in the Pantepui may have had an original Pantepui origin and secondarily dispersed to the Andes. Endemic genera, species, and subspecies of the Pantepui are an important system to generate phylogenetic hypotheses with which we could test the generality of hypotheses regarding the relationship of Andean and Pantepui bird lineages.
Warblers of the genus Myioborus are an appropriate genus to test the generality of these hypotheses. It occurs in montane forests from United States to Argentina, and is one of the few genera with endemic species in the Pantepui region (M. albifacies, M. cardonai, M. castaneocapillus). In this study, I will address the relationships of the avifauna of the tepui highlands of southern Venezuela with such areas as the South American Andes and the northern cordilleras of Venezuela. A phylogenetic hypothesis of the genus Myioborus will allow me to determine if the tepui species are the product of several events of colonization or if, instead, they differentiated in the tepui region (i.e., they are a monophyletic group). Similarly, I will be able to examine the evolutionary history of the M. brunniceps. This group comprises the tepui species as well as one species in the Bolivian and Argentinean Andes and another one in the northeastern cordillera of Venezuela. Knowledge of the relative ages of these species, and between this group and the rest of species within the genus, will be useful to determine if the tepui species were colonized from other regions (tepui species younger than their counterparts in other regions) or if they diversified in the tepui region and later colonized the other geographical regions (tepui species older than their counterparts). Results of these analyses will be an important contribution to furthering our understanding of the speciation of birds in South America. Although comparisons based only on one genus are not a rigorous test of biogeographical hypotheses, this study will nonetheless provide data for comparison with systematic research in other genera with similar distributions (e.g., Basileuterus, Atlapetes, Diglossa). Congruence in biogeographical relationships among several genera would provide support for existing speciation hypotheses, or can be used to develop an alternative general hypothesis.
Publications:
- Alvizu, P., M. Castillo, S. González, J. Pérez, A. Quilici, M. Rada, y M. Yáber. 1988. Confrontación de usos en el Delta del Río Unare. Proyecto AUDUBON-UNARE. Reporte Técnico, Instituto de Recursos Naturales Renovables, Universidad Simón Bolívar, Sartenejas, Venezuela.
Pérez-Emán, J., y A. Paolillo. 1997. Diet of the turtle Peltocephalus dumerilianus (Schweiger) (Testudines, Pelomedusidae) in the Venezuelan Amazonia. Journal of Herpetology 31:173-179.
Pérez-Emán, J. y M. Sosa. 1997. Las comunidades de aves y murciélagos de un bosque húmedo adyacente al Parque Nacional Duida-Marahuaka (Edo. Amazonas). Pp: 323-327. En I. Novo Torres, L.G. Morales, C.T. Rodríguez, G. Martínez, y I. de Hertelendy (Eds.), Ciencia y Conservación en el Sistema de Parques Nacionales de Venezuela: Una Experiencia de Cooperación Interinstitucional. Impresos Altamira S.A., Caracas, Venezuela.
Pérez-Emán, J. 1995. A comparison of bird and bat community structure in a tropical lowland rain forest of Venezuela. M.S. Dissertation, University of Missouri-St. Louis, St. Louis, Missouri, USA.
Sebastiani, M., S. González, M. Castillo, P. Alvizu, M. Oliveira, J. Pérez-Emán, A. Quilici, M. Rada, M. Yáber, y M. Lentino. 1994. Large-scale shrimp farming in coastal wetlands of Venezuela, South America: causes and consequences of land-use conflicts. Environmental Management 18:647-661.
Pérez-Emán, J. 1990. Aspectos básicos de la biología, ecología, y valor socioeconómico del quelonio Cabezón, Peltocephalus dumerilianus (Schweiger)(Testudines, Pelomedusidae) en el Territorio Federal Amazonas, Venezuela. Tesis de Licenciatura, Universidad Simón Bolívar, Sartenejas, Venezuela.
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