Cryptic diversity, evolution, and biogeography of Caribbean Croaking Geckos (Genus: Aristelliger).

Open Access
- Author:
- Cloud, Tiffany Loren
- Graduate Program:
- Biology
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- March 29, 2013
- Committee Members:
- Blair Hedges, Thesis Advisor/Co-Advisor
- Keywords:
- Cryptic Species
Aristelliger
biogeography
phylogeny
evolution
geckos
Caribbean - Abstract:
- The sphaerodactylid gecko genus Aristelliger (Caribbean croaking geckos) currently contains eight described species, all found on Caribbean islands. Mitochondrial DNA (mtDNA) sequence data from 106 specimens representing all eight currently recognized species were used to evaluate the relationships of the species within the genus. The molecular phylogeny of the genus is inconsistent with the current species-level taxonomy. Species delimitation methods indicate that there are as many as 24 species, hidden within the eight currently described species. This was especially true of Aristelliger praesignis (Jamaican Croaking Gecko) which has 10 clades of potential species-status, eight of which are in Jamaica, showing deep genetic divergences. Further support that at least six of these clades represent cryptic species comes from the consistency with which most clades can be differentiated from each of the other clades based on morphological characters. In addition, two clades are sympatric and syntopic at Port Antonio, Portland Parish, Jamaica. Another two clades are nearly sympatric, separated by only about 0.75 km at Port Maria and Cabarita Island, St. Mary Parish, Jamaica. In addition to the high levels of cryptic diversity found within Jamaica, A. georgeensis (St. George Island Gecko)—the only member of this genus found on the mainland—is nested within a clade of A. praesignis from Port Antonio, and is the most recent of the clades to diverge,about 1.5 million years ago (Ma). Based on molecular divergence time estimation and geology, it is likely that this genus originated on Hispaniola between 37 Ma and 23 Ma. From there, a lineage invaded Jamaica giving rise to A. praesignis. There have been three dispersals out of Jamaica giving rise to populations or species elsewhere: two out of northern Jamaica, and one very recently from southwestern Jamaica.