Research

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We address diverse questions and at the foundation of all of these research projects are theories of life history evolution, demographic models, and field and greenhouse experiments.  With this common foundation graduate students in the lab have the opportunity to design their own topics.  For example, a current student, is doing a comparative analysis, using four species of Plantago, to determine how different species alter their allocation of resources between growth (survival) and reproduction, in response to changes in the environment. She is interested in determining how changes in life history at the individual-level may then scale up to affect population dynamics and the distribution of species. Also using experimental field experiments and population models, another student, using a high elevation endemic species, showed that local environmental conditions, not environmental gradients, can be important in structuring a species range.  Both of these projects address basic questions that can inform us about how natural selection on species may change in response to global climate change.  In another conservation-related project a student in the lab designed experiments to determine the impact of an invasive species on the evolution of traits of a native species in the invaded community.  Her study, using two species of Impatiens, showed that the two species have a common pollinator and that, in the presence of the invasive species, the floral morphology of the native species is different due to a change in the direction of natural selection.

We also have a long-term project on aging in Plantago lanceolata that is designed to understand how natural selection influences the expression of traits at the latest stages of the life cycle.  We have shown that this herbaceous plant species does age, in other words it shows a decline in survival, reproduction and physiological traits as an individual gets older.  We have also recently shown that the quality of seed produced by older individuals is lower, which may have cross-generational effects on population growth rates.