In an attempt to accommodate each of two perspectives (nature versus nurture) in the formulation of a developmental framework, two complementary approaches to developmental theory are presented. First, consideration is given to what is now known about the developmental process in general (thought out in terms of the question "Where is the information for development?"). It is concluded that the genome and the environment must interact in development. Furthermore, the environment is best thought of as having a constructive role in the developmental process. The biologically oriented theory of probabilistic epigenesis proves to best accommodate these conclusions. It is argued that this "development from" perspective fails to adequately account for the "central tendencies" of the genome, consideration of which is central to the "development to" perspective in biological and evolutionary thought. Maintaining an interactionist position, the paper concludes that development to an evolutionarily adaptive endstate is environment-expectant. The notion of conditional probabilities in development is presented. Four qualitatively different types of environmental conditions that may be involved in development to species-typical endstates are delineated. (BW)