Molecular Phylogeny and Biogeography of Neotropical Lizards of the Family Diploglossidae

Open Access
Author:
Dennison, Stephanie Lauren
Area of Honors:
Biology
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • S Blair Hedges, Thesis Supervisor
  • Daniel J Cosgrove, Honors Advisor
Keywords:
  • biogeography
  • molecular phylogeny
  • Diploglossidae
Abstract:
The lizard family Diploglossidae is distributed in the West Indies, Central America, and South America. In English speaking countries they are known as galliwasps. As part of an ongoing investigation of the historical biogeography of the West Indies, the phylogenetic relationships and biogeography of these Neotropical lizards were studied. Although several morphological and molecular studies have been conducted in the past, they were limited in scope. Consequently, the phylogenetic relationships, taxonomy, and biogeography of diploglossids remain controversial. The purpose of this thesis, therefore, is to obtain a better understanding of the phylogeny and biogeography of the lizard family Diploglossidae. New DNA sequences were collected from three mitochondrial genes (ND2, 12S, and 16S ribosomal RNA) and one nuclear gene (RAG1) for up to 145 diploglossid lizards and one outgroup species, and subjected to phylogenetic analyses. Based on these analyses, two separate West Indian and Central American lineages of Celestus and Diploglossus were identified, the two tetradactyl genera Sauresia and Wetmorena were found to be nested among West Indian Celestus, and many subspecies and populations of the Genus Celestus and Diploglossus were found to form distinct evolutionary lineages that might warrant recognition of full species. In order to further resolve diploglossid molecular phylogeny, future research in this area should focus on filling in the gaps in the mitochondrial and nuclear sequence data set, as well as continuing to add specimens. In addition, morphological characters should be examined to determine whether some genetically distinct subspecies should be elevated to species. Finally, molecular divergence times should be determined in order to make more specific conclusions regarding biogeography.