Aquatic Sciences Meeting, Albuquerque 2001

SS39 Evolution in Aquatic Environments (Spatial and Temporal Connections)

Date: Monday, February 12, 2001, Time: 2:30:00 PM

Location: Dona Ana

De Stasio, B, T, Lawrence University, Appleton, USA, destasib@lawrence.edu

Emery, A, L, Lawrence University, Appleton, USA, emerya@lawrence.edu

Hillebrand, E, M, Lwawrence University, Appleton, USA,

Doyle, R, A, Cornell University, Ithaca, USA, doyler12@hotmail.com

GENETIC DIVERSITY IN DAPHNIA: COMPARISONS OF EGG BANK AND PLANKTONIC POPULATIONS

The potential for evolutionary change in natural populations depends on genetic diversity. For organisms that undergo dormancy, such as the waterflea Daphnia, genetic diversity stored in the resting egg bank can play an important role in evolutionary dynamics. However, little is known of the changes in genetic diversity that occur between the dormant and active phases of the life cycle when new dormant eggs are again produced. We compared genetic diversity measured by protein electrophoresis of individuals hatched from lake sediments and individuals collected from the plankton during the subsequent spring and summer in two Wisconsin lakes. Daphnia pulicaria in the egg banks of both Bullhead Lake and Lake Winnebago exhibited higher genetic diversity than did the subsequent planktonic populations, and contained alleles that were not observed in the plankton. Allele frequencies in Bullhead shifted in a consistent direction during the seasonal progression, while those in Winnebago changed direction frequently. Consideration of the egg bank along with planktonic phases of the life cycle permits us to examine more completely the action of genetic drift and selection in these populations.

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Aquatic Sciences Meeting, Albuquerque 2001

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