1. Department of Ecology and Evolution; Stony Brook University; Stony Brook NY 11794-5245 USA
2. Department of Biology; University of Richmond; Richmond VA 23173 USA
3. Centre for Macroevolution and Macroecology; Division of Ecology; Evolution and Genetics; Research School of Biology; Australian National University; Canberra ACT 0200 Australia
4. Department of Ecology and Evolutionary Biology; University of Arizona; Tucson AZ 85721-0088 USA