Affiliation: | Department of Mathematical Sciences, Norwegian University of Science and Technology, N-7491 Trondheim, Norway;;Department of Zoology, Norwegian University of Science and Technology, N-7491 Trondheim, Norway;and;Laboratoire d'Ecologie Evolutive Parasitaire, CNRS UMR 2365, Universite Pierre et Marie Curie, Bat. A, 7ème étage, 7 quai St. Bernard, Case 237, F-75252 Paris Cedex 5, France |