Species Delimitation

One of my main research interests is in delimiting evolutionary independent lineages, what most people call "species". Although I primarily perform research on reptiles and amphibians, I am also very interested in developing methods that can be used by a broad array of researchers studying a variety of organisms. Independent lineages are most accurately assessed with multiple pieces of evidence, e.g., morphological, molecular, and ecological interactions. However, the availability and ease of collecting molecular data has made this type of data the common currency of species delimitation. I am currently collaborating with Drs. Mariana Morando and Luciano Avila to delimit species in a group of Liolaemus lizards in Argentina using SNP (single nucleotide polymorphism) data.

The Genomics of Speciation and Hybridization in Liolaemus

I am interested in understanding the evolutionary processes that occur at the boundaries between species. In hybridizing taxa, two parental species may merge into a single (hybrid) population, or species boundaries may be reinforced through natural and/or sexual selection. Of course, may other outcomes in hybrid zones are possible. I have been awarded a DDIG to examine the comparative genomic divergences across three hybrid zones in the Liolaemus fitzingerii group. To the right is my working hypothesis of how hybrid zones have formed in this group. Following glacial retreat ~10,000 years ago, populations moved westward and subsequently came into contact with each other, forming hybrid zones roughly in the areas where they are found today. I have partially sampled one hybrid zone, and will return in the fall of 2015 to sample all three hybrid zones completely. I will use RADseq methods to generate genome-wide SNPs in tandem with whole-genome sequencing to understand hybridization at the genomic-level.