PARENT SESSION
Oral Session # 7: Populations and Genetics.
Presiding: E Sotka
Monday, August 4. 8:00 AM to 11:30 AM, SITCC Meeting Room 106.
Temporal patterns of genetic change in recently established Daphnia populations.
Fox, Jennifer*,1, Hairston, Nelson1, 1 jaf38@cornell.edu, Ithaca, NY
ABSTRACT- Much theoretical and empirical research has focused on the long-term genetic effects of the founding of new populations. Few studies, however, have examined the short-term dynamics of genetic change in populations immediately after establishment. Diapausing eggs of Daphnia remaining in lake sediments provide a means of reconstructing population history and fine-scale temporal changes. We examined the genetic trajectories of Daphnia mendotae populations that recolonized two lakes in upstate New York in recent years. We compared patterns of genetic change in a population founded by a large number of individuals hatching from a local egg bank with those in a population founded by relatively few individuals dispersing into the lake from other sources. We measured variation at microsatellite loci in eggs stored in lake sediments to characterize population genetic structure in each population at different time points following population establishment. Preliminary results suggest that populations within a lake are genetically differentiated over time and there is little evidence of a genetic bottleneck in the population founded by dispersal. The results of this study will help to determine the influence of a standing egg or seed bank on genetic diversity and contribute to our understanding of how genetic variation is maintained in natural populations.
Key words: paleoecology, temporal dispersal, egg bank, population genetics