1. W. K. Kellogg Biological Station, Michigan State University, 3700 East Gull Lake Drive, Hickory Corners, MI 49060, USA
2. Department of Plant Biology, Michigan State University, East Lansing, MI, USA
3. Department of Integrative Biology, Michigan State University, East Lansing, MI, USA
4. Program in Ecology, Evolution and Behavior, Michigan State University, East Lansing, MI, USA
5. Center for Population Biology, University of California - Davis, Davis, CA, USA