ethan@utastro.UUCP (Ethan Vishniac) (05/24/85)
[] One consistent argument in this newsgroup has been over the predictive value of evolutionary theory. The point has been made that we cannot predict the course of evolution based on our present knowledge. The creationists on the net seem to feel that this implies that the theory is devoid of predictive value. A number of people have pointed out that the theory has nevertheless been used, with considerable success, to predict data having to do with evolution (e.g. the sequence of fossils, biochemical relationships, the correspondence between the geological column and the ages of rocks etc.). I wish to address the original point, that evolution is not a predictive theory in the sense of predicting future evolution. Many people, of all persuasions, seem to be willing to accept this. I think that this is not true in principle, but only in practice (at present). After all, we know that genes carry most of the crucial information about an organism from one generation to the next. We are in the process of finding the exact genetic information carried by a number of simple organisms. We have begun to learn how these genes express themselves, and we know how they mutate. The fact that the mutations are random is irrelevant. The expression of the mutations is selected upon. Although some randomness is built in to the process, one should be able, eventually, to derive a probabilistic prediction of future evolution in any specified ecosystem. If the rate of evolution is really determined only by the mutation rate and gradualism is correct, then the probability distribution will tend to be broad. Although it should still carry considerable information. If PE is correct than considerably more precise predicitions will be possible. The point is that such predictions are not impossible on an a priori basis and we have every reason to expect that they will become possible eventually. Verifying such predictions does appear to have problems. "Don't argue with a fool. Ethan Vishniac Borrow his money." {charm,ut-sally,ut-ngp,noao}!utastro!ethan Department of Astronomy University of Texas
ethan@utastro.UUCP (Ethan Vishniac) (05/24/85)
> to the process, one should be able, eventually, to derive a probabilistic > prediction of future evolution in any "specified ecosystem". By a specified ecosystem I meant to include any external factors (asteroids, volcanos etc.) as known. In a laboratory situation when dealing with bacteria or some such this should not be too difficult. "Don't argue with a fool. Ethan Vishniac Borrow his money." {charm,ut-sally,ut-ngp,noao}!utastro!ethan Department of Astronomy University of Texas