Virtual Field Study
Documenting Evolution In Calvert County
Work by Patricia Kelley (University of North Carolina, Wilmington) best documents the evolution of numerous fossilized organisms in the Calvert Cliffs strata. The data presented in this Virtual Field Study is a small subset of the extensive data set published by Kelley (1989), Evolutionary Trends Within Bivalve Prey of Chesapeake Group Naticid Gastropods (Historical Biology, vol. 2, pp. 139-156). Dr. Patricia Kelley, former doctoral student of Stephen J. Gould, examined trends in changing shell characteristics of several genre of bivalve mollusks. Kelley sampled over 3,000 shells per genera through the Calvert, Choptank, and St. Mary's Formations. As she examined changing shell features in several genera tested, Dr. Kelley was able to document two features on two genera of mollusks that demonstrated significant gradual change over time. Those two genre were Astarte and Anadara, and in this module we will present some of Dr. Kelley's data to demonstrate evolution.
Last modified October 06 2008 02:42 PM