1. Center for Population Biology, Department of Evolution and Ecology, College of Biological Sciences, University of California, 1 Shields Avenue, Davis, CA 95616, USA
2. Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4
3. Department of Environmental Life Sciences, Trent University, Peterborough, Ontario, Canada K9J 7B8
4. Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada T6G 2E9
5. Department of Biological Sciences, University of Cincinnati, Cincinnati, OH 445221, USA
6. Department of Biology, Western University, 1151 Richmond St., North, London, Ontario, Canada N6A 5B7