1. CNRS, UPS, ENFA; EDB (Laboratoire Evolution & Diversité Biologique); UMR5174; 118 route de Narbonne F-31062 Toulouse France
2. Université de Toulouse; UMR5174; F-31062 Toulouse France
3. Center for Philosophy of Science; University of Pittsburgh; 817 Cathedral of Learning; Pittsburgh PA 15260 USA