bch@unc.UUCP (Byron Howes ) (02/17/84)
I am not sure whether or not to take Richard Harter's skepticism (or article) seriously, but since he seemed to spend some effort I feel I should reply in kind. He writes: >> One gets tired of this creationist vs evolution chatter. I >>suspect that it is rather obvious to all concerned that no one >>seriously advances creationism unless they are convinced beforehand >>that the Bible is literally true. I think it is also rather obvious >>that few of the contributors to this ongoing debate have any great >>knowledge of either geology, paleontology, biochemistry, or biology. >>The creationists trot their sleazy arguments and their opponents >>get hot under the collar and reply heatedly and largely irrelevently. >>Now that I have offended all parties, I mean to have a bit of fun >>by arguing in behalf of the creationists. Well, Mr. Harter can't think the creationist arguements are *too* sleazy, for what he does is trot a number of them out again for us to see. (Their faces are getting very familiar.) If I didn't know better, I'd say that Mr. Harter was engaging in the tactic of pretending to be neutral about the matter, then becoming convinced before our very eyes. Far be it from me, however, to accuse a fellow netter of intellectual dishonesty. Mr. Harter begins by deliniating three points he is going to argue: >>(a) Abiogenesis is improbable. >>(b) Evolution has not been demonstrated. >>(c) Homo sapiens did not evolve. Point (a) has been discussed in this newsgroup considerably and is beginning to take the form of a knowledgeable discussion of life origins. However, (need I say it again?) abiogenesis is *not* axiomatic to evolutionary theory. While it is a topic worthy of discussion in its own right, let us confine the debate to a single theory and not take on the whole of natural science as "evolution." On point (b) he argues: >>Nonetheless I assert in very few instances have complete >>sequences of transitional forms been found. I suggest that >>the complete sequences that have been found have been >>variations in established forms. For example, eohippus >>becomes larger, the toes fuse together, etc. What we don't >>have are complete sequences where dinosaurs become birds. >>For the most part the paleontological record is broken by >>large gaps. This is to be expected; the ravages of millions >>of years are bound to be severe. The fact remains that the >>record is seriously incomplete. I am beginning to understand why Jay Rosenberg won't talk to anyone who hasn't read Kitcher's book. We do indeed have transitionary forms between dinosaurs and birds. The problem is, we call the critters on one side of this (arbitrary) demarcation dinosaurs (though they don't look like Tyrannosaurus Rex) and the other side birds (though they wouldn't look good in your parakeet cage.) The classification system masks the transition, but it is there. It is difficult, too, to meet the creationist requirement of a "transitionary" form. Is it possible to agree, before reviewing the evidence, what such a critter would be like or what biological attributes it would have? He goes on: >> I do not deny that some evolution of form has occurred. >>I suggest, however, that it has not been demonstrated that >>major revolutions of form occurred. For example, mammals >>and birds have a high, stable body temperature. They have >>elaborate mechanisms, both behavioural and internal, for >>maintaining a constant body temperature. Reptiles and >>amphibians do not. The development of such mechanisms >>would have been a revolution in form. But did any such >>development occur? Can it be demonstrated that it could >>have occurred? In evolutionary biology, it is customary >>to investigate evolutionary scenarios. The general idea >>is that we look at an existing species in an existing >>ecological niche with some particular characteristic and >>look for circumstances in which primitive versions of the >>characteristic might have had a selective advantage. This >>works well enough as long as we are talking about a >>limited range of variation. Moreover, the selection >>mechanism is consistent with the known genetic diversity >>in natural species. >> When we turn to evolution in the large, however, >>we have the difficulty that scenarios are much more vague >>in detail. Moreover we do not know that the postulated >>genetic diversity is possible. That is, to go from A to >>B there must be a change in genetic material. However it >>seems very likely that there are limits to the ways in >>which genes can change. We neither know the limits or >>the requirements. Without this knowledge we don't really >>know what can be achieved by natural selection. Whoa! On the one hand he is complaining about the lack of transitional forms and on the other about the lack of evidence for a revolution in form because all we show evidence of is limited transitional variability in form. Evolution, as I understand it, is a non-directed accretive process. At any given point in time there is merely the expected variability from the modal form. It is only over time that the "revo- lution" can be perceived. Of *course* what we find at any one time is within the limits of natural genetic variability. We should be very concerned if it were not. Evolution is a natural process, not some kind of exceptional event. It sounds as if you are looking for the dinosaur that laid the chicken egg. There is no requirement that *all* of the characteristics which distinguish a species evolve simultaneously. Again, the problem of agreeing upon transitional forms. Finally, we get to (c): >> On to the evolution of man. I will note simply >>that the fossil record is remarkably incomplete. We can >>go back 50,000 years and we find beings that, dressed in >>modern dress, could travel on a New York subway without >>attracting undue attention. Moreover we find evidence >>in their remains of the characteristic paraphenalia of >>humanity. The fossil record fails rapidly before that. >>I will also note that it has been often asserted but >>never shown that the differences in intelligence and >>cultural capability between human beings and their >>anthropoid "relatives" is one of quantity only. The >>unique character of human intelligence is a fact; it's >>nature and origin have not yet been explained. Really? What unique character of human intelligence? If I have been reading accounts of recent research correctly, primate intelligence is a matter of degree, but not necessarily of quality. To be sure, human intelligence has emergent properties over ape intelligence, but ape intellect has emergent properties over monkey intellect. Are humans more different from their relatives than their relatives are from one another? I don't think so. >>Let us postulate an agency or >>agencies, with the ability to manipulate and create >>genetic material, that has intervened from time to >>time during the history of Earth. Some possible >>interventions include introducing life itself and >>creating humanity. These interventions produced >>discontinuities in the history of life that had no >>significant probability of occuring spontaneously. >>This hypothesis is testable in principle; if it is >>found that discontinuities have been found then the >>hypothesis gains weight. Conversely, if no discon- >>tinuities are found or apparent ones are resolved then >>the hypothesis loses force. I think we can go along with this, with certain provisos. We must agree as to what constitutes evidence for a discontinuity. "Gaps" in the fossile record are not, in themselves, sufficient proof of a discontinuity -- they are simply a lack of evidence. What does his hypothesis, if true, predict we should find? Under what circumstances? In other words, I am willing to take him seriously if he outlines a research program which attempts to confirm his hypothesis. This is something creationists have failed to do. >> Finally, I would like to point out that it >>is not unscientific nor a violation of Occam's razor >>to admit the possibility that the intervening agency >>may be supernatural in character. Sorry. I can't go along with this. The hypothesis of a supernatural entity is an *extremely* complicated one with profound ramifications for the relative certainty of any kind of knowledge. It impacts not only evolutionary theory, but the entirety of science and that impact has to be dealt with in the assumption. Again, some have attempted to deal with this in this newsgroup and it is worthy of discussion in its own right. -- "Pay no attention to that man behind the curtain!" Byron Howes UNC - Chapel Hill (decvax!mcnc!unc!bch)