Robert Moss's desire to clarify the meaning of "evolution" for students is one that I share. Unfortunately, in his Opinion piece (R. Moss, "The Problem with Evolution: Where Have We Gone Wrong?", The Scientist, Oct. 13, 1997, page 7), Moss perpetuates an elementary confusion. He writes that evolution "is correctly defined as 'descent with modification.'" Fine. But just a few lines down he agrees with Darwin that evolution is "a process of change over time, by natural selection. Period." Evidence for common descent, however, is not the same as evidence for natural selection.
Scientists ranging from Lamarck to Richard Goldschmidt to Stuart Kauffman and Lynn Margulis, while accepting common descent, have argued that the Darwinian mechanism is inadequate to explain much of evolution. In my book, Darwin's Black Box: The Biochemical Challenge to Evolution (New York, Free Press/Simon and Schuster, 1996), I agree that there has been common descent but ...
