The Definition and Description of a "Transitional"

Maybe I can help contribute to this discussion.Mark24 (evolutionist): A transitional is a form that possesses character states that are part way between two separate taxa, &/or a mix of discrete characters between two taxa.Reply: If we define transitional in this way, then there is truly no organism on the planet (extant or extinct) that could not be considered a transitional, because every organism, no matter how exotic, will have characteristics that are in some way similar to organisms of other taxa. We will simply end up with Darwin Redux’s perspective that every organism that has ever existed (including us) is a transitional form. A definition that explains everything is really no definition at all.Robert Byers (creationist): We Don't believe there are transitionals so our defining what they are or look like is, ah, unnatural.Reply: I think you are overlooking some key points. As a creationist myself, I accept that transitionals did and do exist. The limited number of animals on the Ark subsequently evolved into many of the land animals we see today. Most creationists, whether they know it or not, seem to take this perspective. It would seem that the difference between creation and evolution does not lie in whether or not transitionals existed to bridge organisms to common ancestors. On the contrary, the fundamental difference is that creationists: (a) deny that transitionals linked all major animals groups to a single common ancestor (i.e., they instead propose the existence of numerous common ancestors in the form of kinds); and (b) deny that the stratigraphical sequences of fossils in the geologic record are attributable to evolutionary change (i.e., they propose that the fossil record is the result of non-evolutionary mechanisms).Loudmouth (evolutionist): Creationists claim that that evolutionists have not FOUND any transitional fossils . . . Creationist claim that it isn't transitional because it doesn’t jive with their Bible, a very subjective and empty reason. Instead of giving concrete, objective reasons for rejecting these fossils, creationists instead claim that they SHOULDN'T exist, which, I guess, allows them to ignore their very existence. IOW, creationists are scared so they refuse to look at them or define what a transitional fossil should look like.Reply: Very true. There are many on my side of the debate that refuse to perform research for the reasons you cited. I really see no point in being scared of the facts.Jazz writes: Incredibly, evolutionists explain away amazing similarities between animals they consider to be only distantly related by simply invoking "convergent evolution." Convergent evolution is the unobserved and unexplained process whereby two very different animals independently evolve into two very similar animals by an incredible run of countless lucky mutational coincidences extending over tens of millions of years! It seems that some folks will believe almost anything, as long as it doesn't appear in the Bible.PaulK then responds: For instance dolphins icthyosaurs and sharks share a similar overall form because of the way they live. Convergent evolution is often largely the result of functional constraints - and often the results can be seen to be quite distinct. Convergent evolution is certainly not unexplained and it is clearly evidenced.Reply: I would have to agree with Jazz here. One can pick up any comprehensive paleontology resource to grasp the frequency of alleged evolutionary convergence. For example, Robert L. Carroll’s Vertebrate Paleontology and Evolution and Barbara Stahl’s Vertebrate History: Problems in Evolution cite over 110 examples on the following pages respectively:

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p. 7, 8, 22, 24, 27, 35, 44-45, 54, 74, 88-89, 109, 118, 120, 133, 143, 146-147, 151, 159, 182, 182, 198, 199, 221, 222, 225, 225, 254, 265, 268-269, 276, 282, 289-290, 331, 332, 345, 347, 348, 351, 373, 389, 421, 421, 451, 452, 454, 457, 461, 468, 473-474, 477-478, 478, 483, 484, 492, 513, 516, 517, 518, 519, 523, 525, 531, 532, 547, 552-553, 560

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p. 87, 109, 135, 141-142, 151, 153, 153-154, 157, 158, 161, 164, 180, 188, 190, 221, 221-222, 223-224, 225, 227-228, 234, 235-236, 240-241, 242, 248, 265, 273, 275, 276, 283, 286, 293, 324, 349, 358, 373, 439, 461-462, 486, 490-491, 492, 533, 536

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Among all of these quotes is the following:

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In contrast, biologists working with both modern and extinct groups argue that convergence is very common (Cain 1982; Carroll 1982). Arguments for the close relationship of groups based only on the common presence of derived features are of little value, if convergence is equally or more common than the unique origin of derived characters. (Carroll, p. 9)

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It soon becomes clear that modern evolutionary theorists have turned a massive set of seemingly contradictory data points into supporting evidence. And all of this falls quite nicely into any definition of transitional that we conjure up here. Those fossils that fit the definition support evolutionary theory, while those fossils that do not fit (or contradict) the definition can be explained away by convergence and therefore indirectly . . . support evolution. How convenient.I am still unclear as to how to define transitional in such a way as to provide a possibility for falsification. There is also the possibility that the fossil record is incapable of distinguishing which organisms are truly transitionals and which are not. But if someone were to challenge me for a definition, I suppose I would offer the following:

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A transitional fossil is that which contributes to the demonstration of a lineage of forms which gradually develop morphological/physiological characteristics.

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In any case, whatever definition of transitional that modern evolutionary theorists have decided upon, they are less than shy in admitting their virtual non-existence (except to the general public, of course). A brief look at the evolutionary literature will make this point evident, as Carroll and Stahl (see above) in their paleontology books admitted the failure of the fossil record to demonstrate morphological/physiological change in 239 separate paragraphs.

I do not want to get too far off topic, so I’ll be brief.PaulK: Yet where are the examples that offer evidence of convergence at a scale that would cause serious problems for evolutionary theory?Reply: The concept of convergence is most definitely a problem for evolution via random mutations, simply because of the very fact that all of these instances of parallel evolution must have had fortuitously similar mutations occurring independently from one another. And since mutation is random, the development of major morphological/physiological characteristics multiple times is not what one would expect.You also stated in an earlier post that, convergence typically produces similarities that are seen to be "skin deep" when examined in more detail. But this is not true. There are a multitude of highly specialized structures that appear abruptly in species not closely related. For example:

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The Cypriniformes differ from most teleosts in having the majority of their species specialized as herbivores. The marginal teeth are lost, but the pharyngeal jaws form an effective grinding and crushing apparatus. They have a highly specialized mechanism that protrudes the jaws, as do the spiny teleosts, but it evolved separately in the two groups (Alexander). (Carroll, p. 120)

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Certainly not skin deep.PaulK: And it is certainly false to say that paleontologists have admitted the virtual non-existence of transitional forms. The lack is purely at the level of speciation - which you believe in. The paleontologist usually quoted by creationists on this matter is Stephen Jay Gould - and he claimed that at higher taxonomic levels transitional fossils were abundant.Reply: I find these statements to be illogical. The only possible way to bridge higher taxonomic levels is with lineages of individual forms! If the individual forms are missing, there is no way to bridge the higher taxonomic levels.Edit: I am still especially interested in obtaining a definition of "transitional" that allows the possibility of anomalies (to safely escape the logical fallacy of a Self-Fulfilling prophecy).This message has been edited by Anti-Climacus, 12-07-2004 09:48 PM