Natural Selection and Evolutionary Constraints in an Elevated CO2 Environment

Atmospheric concentrations of carbon dioxide (CO2) are increasing rapidly and within 50 years are expected to increase by more than 30%. Previous studies have shown that increased concentrations of CO2 may affect plant physiology, growth, and ecological communities. Increased concentrations of CO2 may also affect the number of seeds plants produce. This research will investigate whether atmospheric CO2 concentrations alter the relationship between seed production and various measures of plant growth, development, and anti-herbivore defense. CO2 dependent changes in the relationships between plant traits and seed production mean that increased CO2 concentrations may affect patterns of selection acting on plant traits. In other words, the plant traits that confer high seed production in today's atmosphere may not be the same traits that confer high seed production in the near future. Evidence for CO2-dependent differences in selection will mean that evolution may be an important response of natural communities to ongoing climate change.

In addition to examining patterns of selection, the researchers will use genomic technology to investigate whether the genetic basis of seed production, growth, and anti-herbivore defense differ depending on the CO2 environment in which plants are grown. All experimental work will be conducted in an existing NSF-supported Free-Air CO2 Enrichment experiment located at Cedar Creek Natural History Area in Minnesota.

This research will provide inter-disciplinary training opportunities for several undergraduate students, a graduate student, and a post-doctoral researcher. The undergraduate students will work in both the field and laboratory and gain experience with basic principles of experimental design and statistical analyses. The graduate student and post-doctoral researcher will gain expertise in plant physiology, evolution, and statistical analysis.