Doctoral Dissertations

Date of Award

5-1995

Degree Type

Dissertation

Degree Name

Doctor of Philosophy

Major

Zoology

Major Professor

Gary F. McCracken

Committee Members

Sandy Echternacht, Stuart Pimm, John Gittleman, Terry Root

Abstract

This study examines aspects of the population genetics of gaur (Bos gaurus) and Asian elephants (Elephas maximus) as it relates to their conservation. The study of Asian elephants was confined to animals on the Malaysian Peninsula. The study of gaur represent India, Nepal, Thailand, and West Malaysia. Samples from captive and wild animals were collected using an originally designed modular-biopsy unit, attached to an arrow and shot from a crossbow. A detailed description of the design, safety and reliability of this equipment is presented. Total DNA was extracted from skin samples and genetic variability was measured using amplified PCR-product generated from the NADH dehydrogenase-1 region of the mtDNA. Variability was described based on restriction fragment analysis and restriction site mapping. Using restriction fragment pattern analysis and partial endonuclease digestion mapping data, percent nucleotide base substitutions were calculated to measure populational differences and to identify genetically significant units. In gaur, the molecular data do not support subspecies destinctions as evolutionarily distinct units, and challenged the issue of managing populations according to subspecies designations. The implications of this finding are discussed in reference to the management of captive gaur herds in Malaysia, in North American zoos, and for the wild population on the Malaysian Peninsula. The elephant samples showed little variability within the Malaysian population. The observed level of variability was compared to that of several other studies that examine the mtDNA in large mammals and found to be comparable. There was also an apparent lack of geographic structure observed in the molecular data of the elephant population. Threats to the long-term survival of both gaur and elephant populations on the Malaysian Peninsula are presented and ways to protect and maintain genetic variability are discussed. Due to the level of habitat loss, captive propagation and restocking appear to be the best strategy for gaur conservation while a translocation program may be required to maintain the wild elephant population.

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