Evolution 2019: How Many Species of Anolis distichus?

Anolis distichus is a highly variable species from Hispaniola. It’s especially variable in its dewlap color, ranging from white, to orange, to red. In the past, A. distichus has been broken up into 16 subspecies based on its dewlap variation! Previous work by Rich Glor and his students used genetic data to identify six candidate species, although these six candidate species didn’t correspond well with the 16 dewlap-based subspecies. In order to get a better handle on how justified these candidate species are, undergraduate Tanner Myers, working with Pietro Longo Hollanda de Mello and Rich Glor, from the University of Kansas, presented a poster titled Identifying species when boundaries are blurred.

Myers collected morphological data from populations of A. distichus from across Hispaniola. The authors expected their morphological data to also partition along with the previously identified genetic candidate species. They found this to not be the case! When the authors looked at their morphological data (linear body, limb, and head measurements), to see if these 6 candidate species had any morphological divergence, they found no strong pattern. All of the candidate species clustered together to support one morphological group. In the end, the authors suggest that Anolis distichus may represent a highly variable group in in the early stages of speciation, but at this point, they do not support any taxonomic revisions of the species.

Tanner Myers will be starting graduate school with Jamie Oaks at Auburn University in the fall.