Ancestors and variants: tales from the cryptic

Those who work at the interface of development and evolution are united by the conviction that developmental comparisons can shed light on both the ev olution of specific morphologies and the macroevolutionary process itself. In practice, however, the field comprises a diversity of approaches. As the field grows and practitioners attempt to digest a growing mountain of comp arative data, the various approaches of "Evo Devo" have themselves evolved. A meeting organized by the authors and held at the University of Chicago i n the Spring of 1999 illustrated some of these changes. This review will dr aw on its content to discuss recent developments in two areas: the reconstr uction of common ancestors and the developmental basis of evolutionary chan ge.