1. Department of Biological Sciences, University of Alberta, 11455 Saskatchewan Drive, Edmonton, AB T6G 2E9, Canada.
2. Department of Biological Sciences and Department of Computer Science, Dartmouth College, 78 College Street, Hanover, NH 03755, USA.
3. Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biology, University of Oslo, P.O. Box 1066 Blindern, 0316 Oslo, Norway.