Transitional fossils not proof of evolution?

Hello, Alasdair, and welcome to EvC.Good question, and in fact it is one of my favorites. I have already written about this, but I don't remember when or where so I will have to repeat it, I'm afraid. And since randman won't be back for another week, maybe we can have a decent discussion on this topic before it gets chewed up beyond recognition!The reason that transitional fossils are evidence for evolution is that they are exactly what we would see if evolution were true. (By the way, Douglas Theobald has written my favorite web page on the whole internet (and where your picture came from); he also discusses why fossils are good evidence.Basically, if evolution were true, then the Linnaean classification system should indicate the proper family tree relationships between species. Therefore, humans and non-human apes should share a common ancestor. In fact, we can make a scientific prediction: at one time there was a common ancestor for humans and living non-human apes. Therefore, if we are lucky, we might find the fossil remains of creatures that show characteristics intermediate between humans and apes. And we have! These fossils don't have to exist, but they do.This is the main idea. Basing our predictions on the theory of evolution, we have an idea of what types of fossil creatures are possible, and which are not possible.Whales are clearly mammals, and most mammals are terrestrial, and clearly related to other terrestrial animals like reptiles. Therefore, the ancestor of whales must have been terrestrial. A scientific prediction: there once existed, long ago, creatures that showed intermediate characteristics between modern whales and ancient land mammals. And the remains of such creatures have been found! Again, the point is that these fossils did not have to exist, but they do.In embryology, it is known that all vertebrate embryos share certain features in common; one such feature are the pharygeal pouches. In fish, these form the gills (and other structure). In jawed vertebrates, part of these form the jaws. A part of the pharyngeal pouches that forms part of the jaws in reptiles and fish form part of the inner ear in mammals. So a scientific prediction was made: part of the mammalian ear evolved from part of the reptile jaws; therefore there existed creatures with bones that are intermediate between being completely jaw bones and being completely ear bones. And what do you know, they have found fossils with these characteristics are known to exist!Now the point is that these creatures did not have to exist, but they did. The creationist looks at the diversity of life, and it is a random puzzle to her. But an evolutionist sees a definite pattern, and so can make predictions based on this.Bats are mammals. They are actually related (distantly) to primates. It is possible that we will find fossils that show characteristics intermediate between modern bats and ancient arboreal mammals (if we are lucky). Prediction: we will not find fossils intermediate between bats and, say, birds. We will not find fossils intermediate between whales and fish. We will not find fossils intermediate between humans and slugs.So that is why transitional fossils are good evidence for evolution: because the fit the required pattern and are not just a bunch of random animals with no obvious relationships.(By the way, as good as the fossil evidence is, my favorite evidence for evolution is nested hierarchical classification of the species.)

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"Intellectually, scientifically, even artistically, fundamentalism -- biblical literalism -- is a road to nowhere, because it insists on fidelity to revealed truths that are not true." -- Katha Pollitt

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Well, the evolutionary interpretations of the fossil record is mostly based on speculative interpretations.

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Actually, the interpretations are reasonable inferences from the data.-

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IN fact, this tree is what evolutionists assume to be true.

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Actually, this tree is real. It was originally discovered by Linnaeus before Darwin. The tree is not ambiguous, not depending on which characteristics are chosen for the classification. More modern methods replicate the tree, and the tree is statistically robust.Of course, evolution is not the only explanation for such a tree to exist; however, in light of other evidence it is a good explanation, and other data tend to confirm evolution.Here is some more information on the tree, just because the hierarchical classification is my favorite piece of evidence for evolution (even though it is, at best, only indirectly relevant to this thread).-

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Since the line of hominids is deceptive and does not clearly indicate a gradual evolution, any assuptoin of human evolution would be based on just speculations and bias and not on solid scientific evidence.

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Actually, the fossil record of the evolutionary history of humans is one of the best, probably because it is so recent.

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"We must respect the other fellow's religion, but only in the same sense and to the extent that we respect his theory that his wife is beautiful and his children smart."
-- H. L. Mencken (quoted on Panda's Thumb)

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Indeed, this is what the fossil record shows; creatures appearing abruptly and fully formed in various layers of strata.

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And it also shows plenty of instances of transition forms between very different taxa: between fish and tetrapods, between amphibia and mammals, between apes and humans, and so forth.-

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These branching diagrams, which are supposed to show a relative degree of relationships amongst living things, is based on guesswork from appearance.

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Actually not. Get several people to place automobiles in a philogenic tree. You will probably get very different trees depending on how the people choose to organize the automobiles. However, different taxonomists will always produce essentially the same trees; the only differences are usually very minor. This indicates that the tree is real.-

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The plain fact remains that in more conventional depictions of alleged transitional forms, we still find everything fully formed. We find no organisms in any kind of evolutionary limbo.

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Nor does the theory of evolution suggest otherwise. The theory of evolution does not suggest that we should ever find anything other than fully formed organisms. What evolution does suggest is that we should find organisms with characteristics that are in between those of different taxa, and/or mixtures of characteristics of different taxa. And we do, with Acanthostega, Archaeopteryx, and Australopithecus being prime examples.The theory of evolution does not suggest that there should be organisms in some kind of "evolutionary limbo" (whatever that means). What the theory of evolution suggests is that there should be organisms that are in a sort of "taxonomic" limbo, where it is difficult to assign the species definitely to one or another taxa, Archaeopteryx and Australopithecus being good examples of this as well.But if the altruism thread is any indicator, I suspect that you will refuse to understand what the theory of evolution is and what it predicts and what it does not predict, and merely repeat the same assertians over and over again.-

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And there, in the mans own words, he supplants the traditional, gradulaistic argument that you are still maintaining.

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Actually, he doesn't.-

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No, but abiogenesis is an important piece of the puzzle for evolution.

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No, it is not. It is an important puzzle for bi=ology and geology in general, but not for evolution itself.

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"We must respect the other fellow's religion, but only in the same sense and to the extent that we respect his theory that his wife is beautiful and his children smart."
-- H. L. Mencken (quoted on Panda's Thumb)

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I have REPEATEDLY pointed out that no modern evolutionary biologist works from the assumption of phyletic gradualism anymore, and therefore the repeated arguments by NJ and Mr.Matrix against phyletic gradualism are strawmen, and moot.

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And if the altruism thread is any indication, you will coninue to repeatedly point out these basic facts, but NJ will either choose to ignore it or refuse to read it correctly.

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"We must respect the other fellow's religion, but only in the same sense and to the extent that we respect his theory that his wife is beautiful and his children smart."
-- H. L. Mencken (quoted on Panda's Thumb)

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Here's the actual core of the problem. You want to see finely gradated changes not for transitions between species, which you concede happens, but between higher taxa, such as genus, family and order. Unless we get incredibly lucky, we're simply not going to find this. The vagaries and rarity of fossilization make it extremely unlikely.

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What is remarkable is that this is what we see in the fossil record: we do see gradated changes between higher taxa, and some of the gradations are quite fine. What tends to be very rare in the fossil record is gradations between closely related species in the same genus (or even in the same family). There are many lineages that link higher taxa, and the "gap" between inidividual species can easily be bridged by the very species-to-species gradations that creationists are forced to admit are seen in the present day.Creationists are forced to admit the existence of "micro"-evolution. The question is whether these "micro" changes can add up to "macro" evolution -- it is evidence that "macro"-evolution occurred that the fossil record provides.

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"We must respect the other fellow's religion, but only in the same sense and to the extent that we respect his theory that his wife is beautiful and his children smart."
-- H. L. Mencken (quoted on Panda's Thumb)

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PE gives reasons for why we shouldn't expect to find very many transitions in the fossil record, again, presumably to cover up the fact that they simply don't exist.

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Actually, as crashfrog pointed out to you already, Gould and Eldridge were well aware that transitions do exist, and lots of them. What punctuated equilibrium is meant to explain was two common phenomena:(1) Many species exist in the fossil record for long periods of time with very little or no change during this time.(2) There are many examples of species being "suddenly" replaced by new, closely related species, that is, species being replace by similar species that could easily be related through the "micro"-evolution that creationists do accept.Punctuated equilibrium does not, and was not meant to, explain large gaps that exist in the fossil record -- these are already adequately explained by the imperfections of the fossilization process.Punctuated equilibrium was mean to explain the existence of "micro"-gaps that exist.At any rate, creationists still have never provided an adequate explanation of the many, many transitional fossils that exist in the fossil record that give good records of the evolution of important lineages.

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"We must respect the other fellow's religion, but only in the same sense and to the extent that we respect his theory that his wife is beautiful and his children smart."
-- H. L. Mencken (quoted on Panda's Thumb)

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As well, with PE, my concern with PE isn't that they use burst of rapidity in the theorum, but rather, that its being used as a n excuse not to present evidence, or at least, give us reasons why shouldn't expect to see any.

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This of course is completely wrong. It has been pointed out that Punctuated Equibibrium does not explain the lack of fossil transitions. There is no lack of fossil transitions to explain. What Punctuated Equilibrium was meant to explain are two positive observations from the fossil record:(1) Many (but not all!) fossil species clearly do not change or change only very little over very long periods of time; and(2) new species appear abruptly in the fossil record, indicating that they evolved over a relatively short time. However, in these cases, these new species are clearly related to the previous species, and differ only to an extent that is explainable by creationist approved "microevolution".But the most serious error is your belief that there is no evidence for evolution or for Punctuated Equilibrium. The fact is that we have positive evidence of Punctuated Equilibrium model. That is, we have several examples of one species that was apparently replaced abruptly by a descendent species over large geographical region, but a small geographic location provides a detailed account of the gradual transition of the one species into the other.This web-page by Don Lindsay, in the section titled "Is There Any Evidence For Punctuated Equilibrium?", has links to four examples. One of the examples: There you have it. One example of a species that was "suddenly" replaced by a new species. Yet a small location yields the minute gradual transition of the one into the other. Exactly the scenario proposed by Gould and Eldridge.Edited by Chiroptera, : for clarity

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"We must respect the other fellow's religion, but only in the same sense and to the extent that we respect his theory that his wife is beautiful and his children smart."
-- H. L. Mencken (quoted on Panda's Thumb)

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...though note that three Neanderthals are included, and we're already fairly certain they are only cousins, not ancestors....

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It is worth noting that creationists claim that Neanderthals were modern humans. By including the three Neanderthal examples in the graphic, J, K, L, M, and N show a wide range of variation that even creationists are forced to concede exists in a single species. It then becomes much harder to draw a line between an adjacent pair of skulls in the graphic that cleanly separates Human from Ape. The difference between E and G (where some creationists would draw the line) does not seem to me to be greater than that between J and N (which creationists claim are both human).

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"We must respect the other fellow's religion, but only in the same sense and to the extent that we respect his theory that his wife is beautiful and his children smart."
-- H. L. Mencken (quoted on Panda's Thumb)

On the other hand, if a single species can show such wide variation, then why is "macroevolution" between higher taxa so hard to accept?

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"We must respect the other fellow's religion, but only in the same sense and to the extent that we respect his theory that his wife is beautiful and his children smart."
-- H. L. Mencken (quoted on Panda's Thumb)

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I'm not sure how many quotes I need to pull up....

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You can pull up as many quotes as you want, but I have read what Gould actually wrote. I suggest that instead of "pulling up" quotes at random that you read his essays in their entirety. They are not hard to find; if you don't want to spend money buying the books (although I think that they are worth the expense), you can probably find them at your local library. I recommend the collections of his essays that he wrote for Natural History.When you read his actual essays in their entirety, you will recognize that Gould does not deny that there are many important examples of transitional fossil species. What is more, you will see that his explanations of Punctuated Equilibrium are in line with what we are trying to tell you.-

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This is a very convenient excuse to give us whenever there is no change on record.

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There is lots of change on record. There are also lots of examples where a species will exhibit very little change over time. If you would read Gould's essays in their entirety, then you will see that he acknowledges both of these phenomena.-

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this must somehow explain that every living thing is inherently related without any kind of corroboration by providing clear, links in the chain, that I object to.

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There is lots of corraborative evidence, in many different fields of biology.-

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And now PE provides a 'reason' on how we should not expect to find them, or if we do, that they are few and far between.

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No, it does not explain why we should not expect them, especially since there are examples where we do see them. Punctuated Equilibrium is meant to explain what we do see, namely why we sometimes see the gradual changes, and why sometimes we see what appears to be sudden "jumps".-

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I guess its about time to start a thread on the '29 evidences of macroevolution,' presented by TalkOrigins.

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Excellent. I don't know which piece of evidence that you want to start with, but just so you know, my favorite piece of evidence is the nested hierarchical classification of species. Not that you have to start with that particular one, just that this is the one that will spark my interest the most.-I will say this again: the fossil record is marvelous confirmation of the theory of common descent. We see remarkably detailed lineages for several examples of "macroevolution". We see fossil species A then B then C then D and so forth. A and B can easily be connected by the "microevolution" , as can B and C and also C and D. Yet A and D are very different, examples of the type of macroevolution that creationists deny.

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"We must respect the other fellow's religion, but only in the same sense and to the extent that we respect his theory that his wife is beautiful and his children smart."
-- H. L. Mencken (quoted on Panda's Thumb)

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There are no transitional fossils.

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Actually, there are lots of transitional fossils. Lots and lots. In fact, there are more transitional fossils than you can shake a stick at.-

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How did bats evolve? Where are the transitional fossils?

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If bat transitionals were found, would you then accept the theory of evolution? If so, the why don't you accept ape-human transitionals, ungulate-whale transitionals, fish-tetrapod transitionals? If not, then why bring it up?Here is how science works: you make a prediction and then see if the predicted phenomena are observed. Here is my prediction: if and when bat transitionals are found, we will find that they are related to the primitive arboreal mammals that also gave rise to primates. This is because current molecular phylogenies confirm that bats are distant cousins to primates.What we will not see is that pre-bats are related to primitive carnivores. We will definitely not see that proto-bats were related to birds. This is what we predict based on the theory of evolution.So if bat transitionals are discovered, and they have these predicted phylogenic relationships, what will you have to say? (Might be a moot question, since we have no guarantee that bat transitionals will be found. But, heck, we found whale transitionals, so who knows?)-

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I have gone over to the creationist camp, based on evidence, not faith.

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I used to be a creationist, but the evidence has shown me that literal Genesis creationism is untenable. Funny, huh?-The other points in your post are off-topic for this thread.-By the way, welcome to EvC. I look forward to your contributions here.

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"We must respect the other fellow's religion, but only in the same sense and to the extent that we respect his theory that his wife is beautiful and his children smart."
-- H. L. Mencken (quoted on Panda's Thumb)

Welcome back, nemesis.

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I also happen to believe that it provides a satisfying basis to reject the notion and need of a Creator in the minds of countless evolutionists.

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I've already invited you (I think) to the Motivations for Non-belief thread; although I had a different intent in mind for that thread, I don't think it would be inappropriate if you would like to say more on what you think atheists feel in that venue.

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"We must respect the other fellow's religion, but only in the same sense and to the extent that we respect his theory that his wife is beautiful and his children smart."
-- H. L. Mencken (quoted on Panda's Thumb)

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My trip was horrible.

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Ugh. That's too bad. Me, I always enjoyed taking the train between Eugene, Oregon and Seattle, Washington. You are correct that it isn't faster than driving (the tracks aren't designed for the Acela trains to go their designed speed), but to me it was much more pleasant. We have a train track that goes through town here -- I wish Oklahoma would spend a little bit of money to help fund passenger service into Oklahoma City.-

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So, I thought I'd ask you about the particulars on how to request a new thread.

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Ah, just give it a try. If it's not a very good opening post, the mods try to help you write it better. Or check out the current attempts at opening posts in the Proposed New Topics forum -- you might get an idea of what the mods are looking for.

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It seems illogical to think that all these observable changes supposedly occured from a common ancestor to homo sapiens in a shorter time than these million year old animals, such as Limulus polyphemus(horseshoe crab)

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Why is this illogical?At any rate, are you sure that the known fossil specimens of horseshoe crabs are the same species as the modern ones? I suspect, like the Coelecanth, that there are probably some differences.

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"These monkeys are at once the ugliest and the most beautiful creatures on the planet./ And the monkeys don't want to be monkeys; they want to be something else./ But they're not."
-- Ernie Cline

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Wouldn't you think they would have some sort of OBSERVABLE change that we wouldn't need DNA testing to see?

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I don't understand what you mean here. Of course there are observable differences between contemporary and ancient horseshoe crabs. That is why paleaontologists put then in different genera.

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"These monkeys are at once the ugliest and the most beautiful creatures on the planet./ And the monkeys don't want to be monkeys; they want to be something else./ But they're not."
-- Ernie Cline