Comments on the personalities and viewpoints of Richard Leakey and Donald Johanson, paleoanthropologists who hold differing views on the origin of humans. Summarizes major paleoanthropological finds and suggests the use of radio-immunoassay techniques for untangling the human family tree. (JN)

Reviews the pros and cons of using animals or alternatives in scientific research. Such alternatives (as indicated in congressional bill HR 556) include mathematical models, isolated organs, tissue and cell cultures, computer simulations, mechanical models, and "lower" organisms among others. (SK)