Gene flow among populations of the green anole, Anolis carolinensis (Sauria: Polychridae), in the northern extreme of its range : biogeographical implications

Author

Delia Fayth Truett

Date of Award

8-1993

Degree Type

Thesis

Degree Name

Master of Science

Major

Zoology

Major Professor

Arthur C. Echternacht

Committee Members

Gary F. McCracken, David A. Etnier

Abstract

Twelve populations of Anolis carolinensis were studied using allozyme electrophoresis to determine genetic divergence and to postulate historical relationships and dispersal routes. Eight populations were located in East Tennessee along the upper Tennessee River system. An additional population was located on each of three routes that the anoles may have used as they expanded northward into Tennessee. Finally, a population from Louisiana was used as representative of the Gulf coastal plain. As Tennessee anoles are most often located along river banks, the three proposed routes follow major river systems: 1) a western route from the Gulf coastal plain following today's Bear Creek and Tombigbee River, 2) a middle route from the Gulf coastal plain following today's Coosa and Conasauga Rivers, and 3) an eastern route over the continental divide from the Atlantic coastal plain following today's Savannah River. These three routes were compared with the alternative that the anoles dispersed northward in a continuous front disregarding river systems. Nei's (1978) Genetic Identity coefficients based on nine polymorphic loci range from 0.851 to 1.000 with a mean of 0.954. An average F_st value of 0.232 was estimated over all loci and sample sites indicating a large degree of substructuring among the populations sampled. A dendrogram based on Genetic Distance indicates that the populations in East Tennessee are most closely related to the population located along the western route (proposed route 1) and suggest that the anoles may have dispersed northward along this route. A population in the area of Chattanooga, Tennessee, however, shows closer affinities with populations in Georgia and South Carolina, located along proposed routes 2 and 3.

Recommended Citation

Truett, Delia Fayth, "Gene flow among populations of the green anole, Anolis carolinensis (Sauria: Polychridae), in the northern extreme of its range : biogeographical implications. " Master's Thesis, University of Tennessee, 1993.
https://trace.tennessee.edu/utk_gradthes/12039