Phylogenetics, biogeography, and conservation of Caribbean Iguanas (Cyclura and Iguana) /
This study used genetic data to explore evolutionary relationships and population level dynamics of threatened rock iguanas and common iguanas, Cyclura and Iguana. The results are discussed in terms of biogeographic history, prioritization of conservation efforts, and wildlife management. Analysis o...
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
2000.
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| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=728415961&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | This study used genetic data to explore evolutionary relationships and population level dynamics of threatened rock iguanas and common iguanas, Cyclura and Iguana. The results are discussed in terms of biogeographic history, prioritization of conservation efforts, and wildlife management. Analysis of mitochondrial sequence data recovered Cyclura as monophyletic (100% bootstrap support), and not closely related to any other genus, while Iguana was strongly supported as the sister taxon to Sauromalus (78% bootstrap support). Interspecific relationships within Cyclura were fully resolved, however, questions regarding the subspecific taxonomy of C. cychlura, C. nubila, and C. rileyi were raised. C. pinguis and C. collei were ranked the highest with respect to the amount of genetic diversity they contribute to the genus. Calibration of a molecular clock resulted in 1% sequence divergence being equivalent to 1.29 my and suggested that Cyclura colonized the Puerto Rican Bank between 15 and 35 Mya. Eight polymorphic microsatellite loci (2 to 14 alleles) were used in combination with the mitochondrial sequence data to explore patterns of genetic variation within and among island populations of the Bahamian rock iguana, C. cychlura. Genetic data supported two phylogenetically meaningful clades, Andros Island and the Exuma Cays, and indicated that each island population is currently independent demographically. According to the Shannon Index, Andros Island has the highest overall genetic diversity (avg. D = 1.04) while North Adderly Cay has the lowest (avg. D = 0.269). Along with information regarding specific threats to each island population, allelic data were used to discuss conservation management strategies, including prioritization and translocation. Mitochondrial sequence data revealed a high level of differentiation between northern and southern I. iguana populations (avg. 4% sequence divergence), indicating the potential existence of cryptic species within the group. Microsatellite data recovered the same geographically defined clades. The data suggested two separate radiations of Iguana into the Lesser Antilles and a relatively recent radiation northward into Central America. The three sampled populations of I. delicatissima had identical mitochondrial haplotypes and were monomorphic at four microsatellite loci. Conservation issues surrounding iguana farming and the pet trade are discussed in light of these results. |
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| Item Description: | Vita. "Major Subject: Genetics". |
| Physical Description: | ix, 90 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilm Inc. |
| Bibliography: | Includes bibliographical references (leaves 73-87). |