Dear listers, Please could any of you provide me with the complete formula of the Average Taxonomic Distance (Sneath & Sokal 1973)? Many thanks. Salva Salvador Herrando-Pérez BSc MPhil in aquatic ecology ADDRESS C/ Padre Jofre 19,piso 3, pta 7 12006 Castellón de la Plana SPAIN Telephones: (34) 964 038845 / (34) 657 787340 E-mail: [log in to unmask] / [log in to unmask]