Affiliation: | 1. Department of Biology, University of Maryland, 1210 Biology-Psychology Building, College Park, MD, 20742 U.S.A.;2. Department of Statistics, Kansas State University, 205 Dickens Hall, 1116 Mid-Campus Drive North, Manhattan, KS, 66506 U.S.A.;3. Department of Biology, Georgetown University, Reiss Science Building, Room 406, 37th and O Streets, Washington DC, NW, 20057 U.S.A. |