Document Details

Document Type:   Thesis
Title:   Analysis of Genotypic and Phenotypic Differences in Desmognathus quadramaculatus Across the Southern Appalachians
Author:   Deborah Susan Merritt
College:   Science
Degree Program:   Biological Sciences, M.S.
Degree:   Master of Science
Committee Director:   Dr. Thomas K Pauley
Document Availability:   Document available for World-Wide access.
Date of Defense:   4/16/2005

Populations of Desmognathus quadramaculatus were compared for genotypic and phenotypic differences across 5 states in the Southern Appalachians. Series consisting of 10 salamanders each were collected from West Virginia, Virginia, Tennessee, North Carolina and Georgia. Salamanders were assessed for genotypic differences by using allozyme (proteins with polymorphic loci) electrophoresis staining for 13 loci of the muscle, liver and stomach tissue. Nei’s genetic distance was used to score genetic variation between populations. Phenotypic differences were assessed by comparing 10 external morphological measurements between populations. Mahalanobis’ distance was used to score morphological differences between populations. Both genetic and morphological differences were correlated with linear geographic distance (km) between populations (r2= 0.85 and 0.65, respectively). Results of these studies indicate that morphologically cryptic species exist in the D. quadramaculatus complex. However, conflicting results of the morphological and allozyme testing indicate that further research, including DNA sequencing, is necessary to resolve the taxonomic status of this species complex.  

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