jes1@akgub.UUCP (03/31/87)
This is in response to the reference to Dawkins' three books *promoting* Neo-Darwinism (hereinafter just Darwinism). No proof for speciation by natural selection has ever been presented - nor will it ever be - because it does not exist. The supposed process is fictitous. Believers in the Darwinian fantasy seem to think that just because they can verbalize a scenario in the appropriate terms it becomes fact. But the best they can do is: 1. Offer meaningles interpolations of the fossil record. (If it were complete, it would prove Darwinism. It must be incomplete because we *know* Darwinism is true. Therefore we are justified in interpolating "smooth connecting links." It thus proves Darwinism. 2. Offer meaningless extrapolations of observations in nature. (If we could watch long enough, we could see a brand new species arise a gene at a time, not just different beaks or colors, but whole new creatures. Again, you must *assume* Darwinism is true to make such a conclusion.) Many seem to think that Darwinism must be right by default since the only alternative they can see is Creationism. This is more hogwash. Both are wrong. Neither is science. Both are religion. At least the creationists admit to an element of faith. The Darwinists are unable to see that they are no different. Darwinism, in the spirit of the scientific method, is no more than a hypothesis (with ample evidence to refute it), since there has been no observation to qualify it as a theory. There have been many changes in the lifeforms on this planet through time. Many new species have arisen, and many have perished. But this has nothing to do with proving speciation by natural selec- tion. The real process of speciation - whatever it is - is far more sophisticated. Natural selection works to *preserve* species. Recommended reading - Darwin Retired: An Appeal to Reason by Norman MacBeth
jes1@akgub.UUCP (03/31/87)
I neglected to "sign" my posting on Darwinism. Sorry. J.E. Strickling
gallagher@husc4.UUCP (04/06/87)
In article <826@akgub.UUCP> jes1@akgub.UUCP (jes1) writes: >This is in response to the reference to Dawkins' three books >*promoting* Neo-Darwinism (hereinafter just Darwinism). > > No proof for speciation by natural selection has ever been >presented - nor will it ever be - because it does not exist. The >supposed process is fictitous. > > Believers in the Darwinian fantasy seem to think that just >because they can verbalize a scenario in the appropriate terms it >becomes fact. But the best they can do is: > 1. Offer meaningles interpolations of the fossil record. (If > it were complete, it would prove Darwinism. It must be > incomplete because we *know* Darwinism is true. Therefore > we are justified in interpolating "smooth connecting links." > It thus proves Darwinism. > 2. Offer meaningless extrapolations of observations in nature. > (If we could watch long enough, we could see a brand new > species arise a gene at a time, not just different beaks > or colors, but whole new creatures. Again, you must *assume* > Darwinism is true to make such a conclusion.) > J.E. Strickling is presenting arguments against Neo-Darwinism, also known as the New Synthetic Theory, the synthesis of Darwinism and Mendelism developed by Mayr, Simpson, and Dobzhansky in the 1930's and 1940's - a theory which became rather dogmatic in the 1950's. Its dogma can be summed up in the following words by Ernst Mayr (from Animal Species and Evolution (1963), p. 586): The proponents of the synthetic theory maintain that all evolution is due to the accumulation of small genetic changes, guided by natural selection, and that transspecific evolution is nothing but an extrapolation and magnification of the events that take place within populations and species. But as Stephen J. Gould writes, "if Mayr's characterization of the synthetic theory is accurate, then that theory, as a general proposition, is effectively dead, despite its persistence as textbook orthodoxy." (from "Is a new and general theory of evolution emerging?", Paleobiology (1980), Vol. 6, pp. 119-130 - an article well worth reading). The mechanisms of speciation, the relationship between macroevolution and the microevolution we observe in living populations, the definition of and the role of natural selection, the extent to which morphology is adaptive, the scientific status of evolutionary theory, etc. have been the focus of a great deal of debate and research over the past 30 years, and I do indeed believe that a "new and general theory of evolution" is emerging. As to the scientific status of evolutionary theory, Karl Popper did write a series of articles denouncing Darwinism as unscientific, a "metaphysical research program", and in response certain scientists, the "pattern cladists", have advocated removing evolutionary theory from its central place in comparative biology. But Popper and the pattern cladists do not doubt the truth of much of evolutionary theory - they are neither Creationists nor Velikovskians. In particular, it has been shown that Darwin's theory of descent - the theory that different species are descended from a common ancestor - is rigorously testable - it makes quantitative predictions about the existence of nested patterns of similarities among organisms (see Nature, Vol. 297, pp. 197-200; also, Stephen J. Gould's recent article in Natural History). The existence of these patterns shows all rival theories of the relationship among species to be false. In any case, even if evolutionary theory were as unscientific as Popper and J.E. Strickling believe, I do not think this would not make it a religion, as Strickling believes, anymore than, say, "secular humanism" is a religion. Concerning speciation, everything I have seen persuades me that the punctuated equilibrium model is the correct model for speciation among sexually reproducing metazoan animals. The overwhelming evidence for this is the the fact that fossil species are almost invariably static in morphology throughout their entire existence. For evidence of actual speciation events, see: V.N. Ovcharenko, Speciation in Bathonian Brachiopoda from the Pamirs. Paleontological Journal (1969), Vol. 57, pp. 57-63; P.C. Sylvester-Bradley, Speciation Patterns in the Ostracoda. In 5th Annual Symposium on Evolution of Post-Paleozoic Ostracoda, ed. G.A. Hartmann, pp. 29-37; P.G. Williamson, Paleontntological documentation of speciation in Cenozoic molluscs from Turkana basin. Nature 293, pp. 437-43. So, there is evidence! Is the punctuated equilibrium model Darwinian? It is worth noting that Darwin himself wrote in later editions of the Origin of Species: "the periods during which species have been undergoing modification, though very long as measured in years, have probably been short in comparison with the periods during which these same species remained without undergoing any change." Most tend to assign a primary role to selection pressure in speciation (which makes the theory essentially Darwinian), others emphasize the role of chromosomal alterations and gene rearrangement in speciation (see H.L. Carson, The genetics of speciation at the diploid level. American Naturalist (1975), Vol. 109, pp. 83-92). There are still more radical critiques of Darwinism - epigenetics and Neo-Lamarckism - with which I am unfamiliar but which I guess will ultimately be reconciled with the mainstream of evolutionary theory once the role of development and genetic events in evolution are better understood. 3. Concerning natural selection: the idea that natural selection explains everything, that every characteristic of an organism has some functional, adaptive significance unfortunately clings on throughout biology - but it is disappearing in evolutionary theory. People now recognize the contribution of the phylogenetic legacy of the organism, of developmental constraints, of structural constraints, of non-genetic variation due to environmental factors, and of chance to the form of the organism - in addition to the contribution made by the action of natural selection. Gould has an excellent metaphor for this, which comes from Mivart (writing in 1871): the organism is like a polyhedron, which can only stand on one of its faces. "The facets are constraints exerted by the developmental integration of the organisms themselves." Natural selection is the force turning the polyhedron, but the polyhedron can not turn any which way but only onto one of its facets. "Organisms are not billiard balls, struck in deterministic fashion by the cue of natural selection, and rolling to optimal positions on life's table. They influence their own destiny in interesting, complex, and comprehensible ways." (again from "Is a new and general theory of evolution emerging" leobiology (1980), Vol. 6, pp. 119-130. So, I think Strickling's objections to Neo-Darwinism have been addresses by evolutionary theorists themselves - the majority of whom who are, I think, among the most open-minded people in science. In fact, certain theorists, I would say, actually have a great desire to overturn Neo- Darwinism, instead of regarding it as a religion. I suppose anyone who has read this far won't mind reading some more, so I think Strickling's last statement deserves comment, since it touches on one of the greatest issues in evolution - if punctuated equilibrium theory is correct that species maintain their integrity (do not change) through time, then how is this stasis maintained? > Natural selection works to *preserve* species. Some people agree that natural selection maintains species integrity by eliminating any organisms that deviate too far from the population mean, but others believe that the genetic or developmental architecture of the organism in some way prohibits evolutionary change. There are problems with both models, and P.G.Williamson proposes what seems to me to be a very plausible model: individuals that deviate too far from the population norm tend to be developmentally unstable; they generally could survive in their environments but do nor due to competition with the more normal individuals in the population. This is supported by the observation of "population flushes". For example, Ford and Ford observed that during a period of rapid population increase in the butterfly Euphydras aurinia, extremely deformed, even flightless, individuals, survived to maturity; these disappeared once the population stabilized. Also, when the gamefish Bairdella icistius and Cynoscion xanthulus were introduced into the Salton Sea on the Colorado River delta, extremely abnormal individuals (reversed vertebral columns, lack of jaws, eyes, gill covers, etc.) survived in the absence of any competition. These no longer appeared once the population stabilized after 3 generations. It is possible, that this population flush-and-crash, probably in combination with strong directional selection within small populations - may be the major mechanism of speciation in animals. (Also, some recently rediscovered research on shells carried out over a hundred year period - the most intensive study of variation within species ever performed - shows that an extremely diverse array of deviants survived to maturity - proving that the great variation that is necessary for evolution to work upon does exist.) So, in conclusion, this is a very exciting time in evolutionary biology and systematics, and it would be very sad for anyone out of disgust with Neo-Darwinism to turn to Creationism or Velikovskianism. Paul Gallagher