1. University of Eastern Finland, Department of Environmental and Biological Sciences, P.O. Box 111, FI-80101 Joensuu, Finland.
2. University of Helsinki, Organismal and Evolutionary Biology Research Programme, P.O. Box 65, FI-00014 Helsinki, Finland.
3. University of Geneva, Department of Genetics and Evolution, Quai Ernest-Ansermet 30, 1205 Geneva, Switzerland.
4. Natural Resources Institute Finland (Luke), Aquatic Population Dynamics, P.O. Box 413, FI-90014 University of Oulu, Finland.
5. Natural Resources Institute Finland (Luke), Aquatic Population Dynamics, Manamansalontie 90, FI-88300 Paltamo, Finland.