Several case studies of research into the biological needs of communities in developing countries were conducted and two strategies for relating biological education (in both formal and nonformal contexts) to community development were identified. Four of these case studies are presented. They are: (1) "From Biological Knowledge to Community Development" (Abraham Blum), in which a tentative model describing six factors of applying biological knowledge to community development is presented and illustrated in the case study; (2) "Concepts and Perceptions about the Environment of People in an Upland Community" (Dolores Hernandez); (3) "Concept of Health and Aging among Children of a Fishing Community" (Dolores Hernandez); and (4) "Assessment of Community Needs in Mauritius - The Gap between Commonly Believed and Actually Expressed Needs" (Michael Atchia). Each study includes background information, rationale, methodology, results, conclusions, and educational implications. The two strategies for community-based biological education are outlined in the introduction. There is an output model (in which biological knowledge possessed by a small human community is studied, with reference to how this knowledge is used in solving the community's needs) and an input model, which implies an input of biological knowledge into a community to achieve development under one or several aspects. (JN)