Molecular Phylogeny and Speciation in Hispaniolan Lizards of the Anolis cybotes Species Group

Open Access
Bruce, Laura Jean
Area of Honors:
Bachelor of Science
Document Type:
Thesis Supervisors:
  • S Blair Hedges, Thesis Supervisor
  • Richard Cyr, Thesis Supervisor
  • Michael Axtell, Honors Advisor
  • adaptive radiation
  • evolution
  • taxonomy
  • Anolis cybotes
  • anoles
  • Hispaniola
  • biodiversity
  • speciation
  • molecular phylogeny
Iguanian lizards of the genus Anolis form the most species-rich genus of terrestrial vertebrates, including approximately 400 species that provide identifiable evidence of adaptive radiation. Anoles are notable for their throat dewlaps, subdigital toepads, and exceptional diversity. The diverse Anolis cybotes species group encompasses the trunk-ground ecomorph class of anoles on the island of Hispaniola. Previous work has provided evidence of an evolutionary radiation within the Anolis cybotes species group that is associated with specialization for different macrohabitat types (Glor et al. 2003). Yet, the extent of species divergence remains largely undocumented, and taxonomic accounts are in conflict regarding subspecies and usage of taxonomic names. This study expands upon a previously conducted molecular genetic analysis, with the overall goal of elucidating the diversification that has occurred in the Anolis cybotes species group of trunk-ground anoles. Four mitochondrial genes (tRNAMet, ND2, tRNATrp, and tRNAAla) were sequenced for 73 new specimens belonging to the Anolis cybotes species group and for one specimen from an outgroup species. These data were combined with 113 specimen sequences from previous studies and used to generate a maximum likelihood phylogenetic tree. The results of this study suggest that significant taxonomic changes in the Anolis cybotes species group are warranted in order to accurately characterize the cybotoid anoles. These results and future studies in this field are crucial to elucidating the diversification in these anoles, understanding the evolutionary process of adaptive radiation, and demonstrating the need for improved biodiversity conservation efforts in the Caribbean.