1. Department of Biology, University College London, 4 Stephenson Way, London NW1 2HE, UK
2. Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, UK
3. Institute of Cell, Animal and Population Biology, Ashworth Laboratories, King's Buildings, West Mains Road, University of Edinburgh, Edinburgh EH9 3JT, UK
4. Vavilov Institute of General Genetics, Gubkhin Street 3, Moscow 117809, Russia
5. Department of Biology, University of Rochester, Rochester, NY 14627, USA
6. Department of Entomology, Agricultural University of Wageningen, PO Box 8031, 6700 EH Wageningen, The Netherlands