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Professor of Zoology
Director, The University of Oklahoma Biological StationPhone: (405)325-4766/7438
Fax: (405)325-6202RM/Lab:SH106A
Dr. Weider's web page
Current Research Interests and Subject Areas Available for Graduate Research
My group and I study the mechanisms (e.g. selection, migration) that influence the maintenance of genetic diversity in asexual-sexual species complexes, using the freshwater cladoceran genus, Daphnia, as our primary model organism. My research bridges the fields of population genetics and evolutionary ecology. In my lab, a variety of molecular techniques (e.g. allozymes, PCR-based RFLPs, microsatellites, DNA sequencing) are used to examine the population genetic structure of aquatic organisms, with most of my work focusing on zooplankton. We currently have several major projects. The first project has been examining the phylogeography and phylogenetics of the circumarctic Daphnia pulex complex in collaboration with colleagues from Norway and Canada. Two main goals are to obtain baseline data on levels of (bio)genetic diversity across the entire circumarctic range of this complex, and to examine phylogeographic patterning related to past climatic (Pleistocene glaciations) events. These data provide an unparalleled look at the distribution of genetic (clonal) diversity in an asexual species complex. The second project has focused on the ecological and genetic information held in lake/pond sediment egg banks of freshwater invertebrates, primarily Daphnia. We employ a variety of molecular (e.g. microsatellites, mtDNA RFLPs, allozymes) and ecological (i.e. direct hatching of eggs) techniques to examine long-term (i.e. decades, centuries) shifts in population genetic structure that may be associated with concomitant shifts in environmental factors that may influence long-term temporal genetic heterogeneity in natural populations.
In addition, we are delving into the relationship between elemental composition (biological stoichiometry - C:N:P), rDNA structure, growth rates, and selection, using the freshwater microcrustacean, Daphnia, as our model organism. This is part of a much larger NSF-sponsored project with colleagues at Arizona State Univ., U. of Arizona, U. of Minnesota, and U. of Maryland.
To learn more about this research, visit Dr. Weider's web page.
B.A., St. Bonaventure University
Selected publications:
Hessen, D.O., P.D. Jeyasingh, M. Neiman, and L.J. Weider. 2010. Genome streamlining and the elemental costs of growth. Trends in Ecology & Evolution (in press).
Jeyasingh, P.D., L.J. Weider, and R.W. Sterner. 2009. Genetically-based trade-offs in response to stoichiometric food quality influence competition in a keystone aquatic herbivore. Ecology Letters (in press).
Weider, L.J. , P.D. Jeyasingh, and K.G. Looper. 2008. Stoichiometric differences in food quality: impacts on genetic diversity and coexistence of aquatic herbivores in a Daphnia hybrid complex. Oecologia 158:47-55.Jeyasingh, P.D. and Weider, L.J. 2007. Fundamental links between genes and elements: evolutionary relevance of ecological stoichiometry. Molecular Ecology (invited review) 16:4649-4661.
Weider, L.J., J.J. Elser, T.J. Crease, M. Mateos, J. Cotner, and T. Markow. 2005. The functional significance of ribosomal(r)DNA variation: Impacts on the evolutionary ecology of organisms. Annual Review Ecology Evolution Systematics 36:219-242.
Jeyasingh, P.D. and L.J. Weider. 2005. Phosphorus availability mediates plasticity in life history traits and predator-prey interactions in Daphnia. Ecology Letters 8:1021-1028.
Weider, L.J., W. Makino, K. Acharya, K.L. Glenn, M. Kyle, J. Urabe and J.J. Elser. 2005.Genotype x environment interactions, stoichiometric food quality effects, and clonal coexistence in Daphnia pulex. Oecologia 143:537-547.
Weider, L.J. and A. Hobæk. 2003. Glacial refugia, haplotype distributions, and clonal richness in the Daphnia pulex complex in arctic Canada. Molecular Ecology 12:463-473.
Limburg, P.A. and L.J. Weider. 2002. "Ancient" DNA in a microcrustacean resting egg bank can serve as a paleolimnological database. Proc. R. Soc. Lond. Series B. 269:281-287.
Elser, J.J., R.W. Sterner, E. Gorokhova, W.Fagan, T. Markow, J. Cotner, J. Harrison, S.Hobbie, G. Odell, and L.J. Weider. 2000. Biological stoichiometry from genes to ecosystems. Ecology Letters 3:540-550.
Hairston, N.G. Jr., W. Lampert, C. Cáceres, C.L. Holtmeier, L. J. Weider, U. Gaedke, J.M. Fisher, J. A. Fox, and D. M. Post. 1999. Rapid evolution revealed by dormant eggs. Nature 401:446.
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