MASTER OF SCIENCE IN BIOLOGY

I would like to thank the people who have contributed in so many ways to shape and form the biologist I am today. I thank Lilian de Prada, my biologist teacher at Gimnasio Iragua, because through her classes I realized that science was the path I wanted to follow. I will always be thankful to Alberto Acosta, my first advisor, from who I learnt all the steps involved in a research project and how fulfilling doing research can be. I thank Julio Mario Hoyoz and Luz Mercedes Santamaria for supporting my desire to pursue this Masters. I also thank Andres Acosta, for my first herping experience and discussing the many ideas for doing research in Colombia. My field work in Mexico could not have been possible without the collaboration and support from Oscar Flores-Villela. I am very thankful for his hospitality in Mexico as well as his valuable comments on my presentation for Cuba. I thank the following individuals for their assistance in the field, most of which traveled with me through the different southern states of Mexico: Saul Lopez, Martha Calderon, Uri Garcia, Robert Jadin and Cristian Blancas. I specially thank Martha Calderon for her valuable assistance with the molecular work and introducing me to the wonders of phylogenetic analyses. I also thank Robert Jadin for his assistance with several phylogenetic programs. iii I am very thankful for all the experiences I got to live in the Smith Lab. I thank all its members, Coleman Sheehy, Jeff Streicher and Thomas Eimermacher in particular, for their great collaboration and for being the main source of critiques and feed backs on my research; I could not have had better lab mates and better friends. I thank Jesse Meik for his assistance with the statistical analyses and great discussions over scalation patterns. I thank Walter Schargel for his collaboration on using DIVA and MAXENT software