The genus Ctenosaura (spiny-tailed iguanas) represents the most diverse group of iguanas with 18 currently recognized species. Ctenosaura similis has the most widespread ranges of all the Ctenosaura species, and extends from southern Mexico to Panama including many coastal islands. The purpose of this study is to explore the genetic diversity within C. similis and look for correlations between genetic relationships and biogeographic patterns related to the spread of the species. This study sequenced and aligned 1140 bp from the cytochrome b (cytb) locus for 159 individuals and 847-878 bp from the rhodopsin locus for 127 individuals. A total of 71 mtDNA and 40 nuclear haplotypes were detected. C.similis has successfully occupied and dispersed in Central America and Southern Mexico with at least 2-3 million-year history. Costa Rica and Panama region can be the origin of this species due to high haplotype diversity, and deeper splits between existing haplotypes are visible on both gene trees and networks. Less haplotype diversity is observed on the Pacific Coast. In most cases, there is still ongoing gene flow, migration on both coasts from South (Costa Rica-Panama) to North (The Isthmus of Mexico) especially on the Atlantic coast. There is no clear separation based on geographical distribution except recent dispersal for small clades in certain areas. Gene trees and networks are consistent to each other for each locus. However, the general pattern of the rod and cytb gene trees/networks does not exactly match each other. There is a consistency between the genetic distance and number of haplotypes (cytb: 3.7%, 71 haplotypes; rhodopsin: 1.85%, 40 haplotypes). The geographic distribution of C. similis has provided valuable information about the spread of iguanas in Central America. These two molecular markers offered important information about the evolutionary historical expansion of C.similis individuals in Central America. Monitoring Ctenosaura similis is necessary for (1) conservation in existing habitats, and (2) invasive potential in new habitats (e.g.Florida and Northern SA).

Library of Congress Subject Headings

Ctenosaura similis--Geographical distribution; Phylogeography

Publication Date


Document Type


Student Type


Degree Name

Bioinformatics (MS)

Department, Program, or Center

Thomas H. Gosnell School of Life Sciences (COS)


Larry J. Buckley

Advisor/Committee Member

Michael V. Osier

Advisor/Committee Member

David Lawlor


Physical copy available from RIT's Wallace Library at QL666.L25 O98 2015


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