Author Affiliations +
Paul Verdu,1,* Giovanni Destro-Bisol2,3
11Department of Biology, Stanford University, Stanford, CA 94305, USA.
22Dipaitimento di Biologia Ambientale, Università di Roma “La Sapienza.”
33Istituto Italiano di Antropologia, Roma.
*Correspondence to: Paul Verdu, Department of Biology, Stanford University, 371 Serra Mall, Stanford CA 94305, USA. Tel: 1-650-724-5122, Fax: 1-650-724-5114. E-mail: verdu@stanford.edu.