My primary focus of study involves the herpetofauna of the neotropics: from biological surveys to phylogeography, as well as the evolution of complex evolutionary traits.

I am deeply interested in the phylogeography of tropical biota, and how biotic and abiotic factors influence the evolution of morphological traits, such as coloration in coral snakes. I am also interested in the evolutionary process of mimicry in snakes, particularly asking why coral snakes have so much variation in the color patterns across their geographical range.

 

Evolution of color polymorphism in Coral snakes

As part of my dissertation, I am studying the systematic relationships of a group of neotropical coral snakes, the Micrurus diastema group. I am interested in this group because they range from the US to Honduras, expanding a vast range of habitat types and present a diverse array of color patterns. Along with next generation sequencing methods, I am studying museum specimens to quantify the extent of color variation. I am pairing this work with geographic information systems (GIS) to test several hypotheses related to the evolution of color pattern in this group.

                                                                                                    Micrurus distans oliveri from Minatitlán, Colima, Mexico

Phylogeography of the snake genus Coniophanes

Along with the previous study of coral snake systematics, I am also studying the phylogeography of an obscure group of colubrid snakes: the black striped snakes of the genus Coniophanes, which range form the US to Peru. These species occur in many habitats and present a vast array of ecological niches and body types. For example,  species can be very large and almost entirely aquatic while others inhabit very dry environments. There are even minute forms restricted to high elevations. Notably, this group also presents extremely diverse hemipenial morphologies (hemipene = the male sexual organs of snakes).

                                                                            Coniophanes alvarezi from near San Cristobal de las Casas, Chiapas, Mexico

                                                                            Coniophanes alvarezi from near San Cristobal de las Casas, Chiapas, Mexico

Evolution of venom

I am also interested in the evolution of complex phenotypes, such as the evolution of venom in snakes. This topic has received vast amount of attention, and with the recent widespread access to next generation sequencing techniques it has become common practice to study the transcriptome of the venom gland of snakes. However, the expression patterns of venom genes and their homologs in other organs remains largely unstudied, as well as the expression of the genes that became recruited into venom genes. We ask if genes with particular expression profiles are more likely to be recruited into venoms (see publications page).

                                                       Skulls of burmese python (Python molurus; left) and the  black-tailed rattlesnake (Crotalus molossus; right)

Systematics of direct developing frogs

Recently a few colleagues and I started studying the systematics and taxonomy of the the subgenus Syrrhophus of Eleutherodactylus, a group of direct developing frogs that range from the US to Guatemala. These are some of the most understudied but possibly one of the most diverse frogs in Mexico.

                                                                              Eleutherodactylus (Syrrhophus) grunwaldi from  Sierra Manantlán, Colima, Mexico.

                                                                              Eleutherodactylus (Syrrhophus) grunwaldi from  Sierra Manantlán, Colima, Mexico.

Herpetofauna of Colima and surrounding areas

As a mid to long term project, I have been working on a guide to the herpetofauna of Colima and surrounding areas in Mexico. Colima is one of the smallest states in Mexico, with less than 6,000 square km, however, it presents a very diverse herpetofauna for its small size, with more than 160 species of amphibians and reptiles.

Adaptation to high elevations in African Amphibians

 

Systematics and Phylogeography of Ethiopian frog