Affiliation: | aHoward Hughes Medical Institute and Department of Ecology and Evolutionary Biology,University of Michigan, Ann Arbor, MI 48109-1048; ;bDepartment of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544-1003; and ;cDepartment of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, University of London, London WC1E 7HT, United Kingdom |