1. Odum School of Ecology and Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA.
2. Department of Biology, Emory University, Atlanta, GA 30322, USA.
3. Rocky Mountain Biological Laboratory, Crested Butte, CO 81224, USA.
4. Department of Biology, University of Maryland, College Park, MD 20742, USA.
5. School of Natural Sciences, University of California Merced, Merced, CA 95343, USA.
6. Program in Computational Biology, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA.