Stephen P. Broker
In the previous sections of this narrative, the attempt has been made to illustrate some of the changes in thinking that have occurred in interpreting the fossil record and explaining the mechanisms of evolution. Historical considerations are useful in pointing out that both the physical and the biological sciences are in a continual state of flux. The sciences attempt to describe natural events in an orderly fashion. The history of scientific thought involves a succession of models—called paradigms by Thomas S. Kuhn—for describing as accurately as possible those natural events. The paradigms are essentially the consensus opinions in the various disciplines of science, and they may be regarded as forms of dogma. Scientific research in effect involves an attempt to fit acquired data to the existing paradigms. A paradigm provides a foundation on which continued scientific work builds.
Darwinian evolution, for example, is a current form of scientific dogma, as is the “holy trinity” of DNA, RNA, and Protein in the areas of genetics and protein synthesis. Kuhn calls this reliance on paradigms “normal science.” During those occasional moments in the history of a science when anomalies surface which will not fit into the existing paradigm, a crisis in science results. When a new paradigm which better explains observable phenomena is formulated, what Kuhn calls a scientific revolution takes place. The old paradigm is discarded and the new one becomes dogma.
The above statements are a poor attempt at summarizing Kuhn’s views of the scientific process. They do indicate that science is not merely a gradual accumulation of knowledge. It is, however, correct to say that science is an attempt to describe “truth” and “reality” in more accurate terms. I prefer terms such as “truth” and “reality” to “fact” in talking about science, for we know that today’s facts are tomorrow’s myths. Good scientists may be staunch supporters of their paradigms, but they keep in the backs of their minds the awareness that some of what they avow will ultimately be discarded. The two quotations that follow, the first by Karl Pearson and the second by W.E. LeGros Clark, provide clear perspective for an understanding of the workings of science.
Science consists not in absolute knowledge, but in the statement of the probable on the basis of our present—invariably limitedacquaintance with facts.1
[Working hypotheses] form the basis of research projects. In due course, new evidence usually requires the modification, if not the abandonment, of such hypotheses. This, however, is how the scientific method works. It amounts to a stepbystep and ever closer approximation to the truth, and implies that all hypotheses, unless they take a very general form . . . are necessarily going to be superseded as science progresses.2
This concept is perhaps the most basic one that a science teacher can hose to communicate to his students.