bch@unc.UUCP (Byron Howes ) (02/26/84)
Richard Harter writes (I think): >> This is in way of reply to Byron Howes. First of all, Byron, >>I hope that this won't offend you, but boy are you gullible. For the >>record I am an atheist, and assess the credibility of creationism to be >>on a par with Velikovsky, Daniel Home, and the tooth fairy. Also >>for the record I have read Kitchner, the Origin of Species (honest!), >>and a large number of other works on evolution, origins, artificial >>intelligence, and philosophy. Kitchner's book, incidentally, >>disappointed me. I felt it ran too much to muckraking and was far >>too diffuse. Well, I don't know whether I'm gullible or not for responding to your arguments instead of to your professed beliefs. For the record, I am definitely not an atheist and, in fact, claim christianity of a sort. Does this mean that I should not be arguing against creationism? Had you read Kitcher well, you would have understood my argument about the speciousness of the "no transitional fossiles" issue. As it is, you seem to have fallen into precisely the kind of trap it offers: >> However, the points that I made in the article are all >>more or less valid. For example, there are no known significant >>transitional forms between the dinosaurs and the birds. Archaeopteryx >>is pretty clearly a feathered reptile; it could never have flown. >>There is a distinct possiblity that it is not in the line of >>descent of birds at all -- merely an interesting precursor in a >>line that died out. What sorts of things *would* you accept as transitional forms, if not "feathered reptiles?" Certainly the (presumed) inability to fly does not disadmit archaeopteryx/archaeornyx as birds, nor does it necessarily classify them as reptiles. You seem to be defining your own classifications and not telling us what they are. >> Evolution must, of necessity, work by accretion. There >>are, however, some real problems with the evolutionary schema. >>Principally these are a consequence of the fact that we don't >>know very much. Remember that a single cell is a system rather >>more complicated than any modern operating system and that a >>multicellular organism consists of trillions of cells also >>organized in a bewildering complex system. Suspose a single >>gene mutates so that it produces a slightly different protein. >>We are not able to say if the impact will be beneficial, >>deleterious, indifferent, or indeed, what they impact will >>be at all. (Except in rare cases.) As a consequence of our >>level of ignorance, we do not know what the possible options >>are for the evolutionary process, i.e. we do not know what >>increments are potentially available. I think we can do better than that. We certainly have a fair idea of what sort of variation can be expected by looking at living populations. If we assume that some point within the manifold which represents genetic variation within that population is representative of the centrum of some potential population with its own range of variation, etc, etc we can see that ultimately the range is quite large within the constraints of viability. Although the range within any given population may be limited, the range of successive populations is quite large indeed. That we don't know the molecular mechanism and all possible outcomes seems irrelevant to the explanatory power of the theory. >> Another kind of ignorance is that we know almost >>nothing of the internal physiology of deceased lifeforms. >>Were the dinosaurs warm-blooded? The current view seems >>to be that most of them stabilised temperatures with thermal >>inertia; a minority view holds that they used active biological >>mechanisms for temperature stabilization. What do we know >>of the glands, the organs, the circulatory systems, the >>hormonal systems of deceased species? Virtually nothing. >>What do we know about the possible evolution of internal >>physiology? Even less. So? What are you trying to say here? That evolution cannot be confirmed until we somehow do autopsies on all relevant critters? Are you saying that if we backtrack on the skeletal, skin, and digestive evidence we do have (which allows us to make more inferences than you might believe about internal characteristics of long-dead creatures) this is insufficient confirmatory evidence for evolutionary theory? What does it matter if dinosaurs were cold-blooded, warm-blooded or (as could be expected) some of both in terms of evolutionary theory? If all you are saying is that there are lots of things we don't know, I will certainly agree. That does not mean, however, that we cannot build a remarkably good case with what we *do* know. >> The fundamental point here is that not all transitions >>are possible. There are adaptive limitations -- all of the >>transitional forms must survive. There are also biochemical >>limitations -- it must be possible for the postulated changes >>to occur. We understand virtually nothing of the latter >>limitations and damned little of the former. Furthermore, >>we do not know enough to know whether the limitations matter. I think underlying this is some notion that evolution is a directed process, that we move directly from reptile to bird with no sidetrack. Evolution does not specify or require this. There can be sideways and retrograde (in terms of the ultimate result) transitions. Again, it sounds like you are looking for the dinosaur that laid the chicken egg or perhaps you are looking for something similar to Lon Chaney changing into The Werewolf -- various cleanly-defined stages along a straight line continuum. This strikes me as a sort of pinheaded view of evolution. >> In actual fact the postulated evolutionary history of life >>deals with only a small percentage of life, deals only with >>selected features, and relies on the existence of postulated >>mechanisms that are not understood. Furthermore, the evolutionary >>scenarios are much more in the line of plausibility arguments >>rather than actual attempts at reconstruction. That is, a >>scenario outlines a possible scenario, and provides some >>cues to checking the feasibility of that scenario. It doesn't >>directly eliminate other scenarios. In short, the evolutionary >>process and life itself is not well understood enough to >>directly assess the validity of evolution. Well, you have just managed to make it impossible to directly assess the validity of about 90% of science. At some level, *all* of science is susceptible to this criticism as we can only argue plausibly about the essential building blocks of the universe. If you are trying to tell us we can't *prove* evolution, I got news for you. Science can't *prove* anything, it can only fail to disprove things. If a theory, like creationism, is not ameinable to that form of analysis, it isn't science. Now, I am certainly willing to entertain any kind of interventionist hypothesis that is capable of spawning some sort of research program with the inherent possibility of disprovability. Certainly creation- ism in both its Biblical and secular forms has failed to come up with such a thing. Shaking sticks at evolutionary theory does not con- stitute such a program as it does nothing to improve explanation over that which evolution (bolstered by a fairly massive amount of evidence) offers. Saying that evolutionary theory doesn't offer as find a mesh of explanation as you feel is necessary doesn't admit interventionist theory either. Again, you offer no further explanatory power than we already have. Come back when you have something in hand. -- "Pay no attention to that man behind the curtain!" Byron Howes UNC - Chapel Hill (decvax!mcnc!unc!bch)