Department of Ecology and Evolutionary Biology, Department of Mathematics, University of California, Irvine, Irvine, California, United States of America.|Department of Veterinary and Biomedical Sciences, University of Minnesota, St. Paul, Minnesota, United States of America.|Department of Basic Science, New York University College of Dentistry, New York, New York, United States of America.|Division of Infectious Diseases, University of Arizona, Tucson, Arizona, United States of America.