Uncommon Descent Serving The Intelligent Design Community

Another rabbit jumps the hat: 419 mya JAWED fish

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Remember we were discussing how current Darwinian evolution theory would not be challenged even if a modern rabbit were found back in the 550 mya Cambrian era (and Darwin followers in the combox appeared to agree).

Hippety hop. A 419 mya jawed vertebrate.

The ancestors of modern jawed vertebrates are commonly portrayed as fishes with a shark-like appearance. But a stunning fossil discovery from China puts a new face on the original jawed vertebrate. [US$18 paywall]

National Geographic News reports*,

“Entelognathus primordialis is one of the earliest, and certainly the most primitive, fossil fish that has the same jawbones as modern bony fishes and land vertebrates including ourselves,” said study co-author Min Zhu of the Chinese Academy of Sciences in Beijing.

But in the new fossil, found in China, has a distinctive three-bone system still used by chewing vertebrates today: a lower jawbone called the dentary and two upper jaw bones called the premaxilla (holding the front teeth) and the maxilla (holding the canine and cheek teeth).

“The exciting thing about this fossil is that when you look at the top of it, it looks like a placoderm, but when you look at the side of the fish and the structure of the jaw, it doesn’t look like any placoderm that we know of,” Friedman said.

“This tends to suggest the exciting possibility that these jawbones evolved way deep down in the lineage, so these features we used to hold as being unique to bony fishes may not be so unique.”

In other words, less evolution and more stasis.

The fish seems to lave lived at the end of the Silurian period, 443 mya to 417 mya.

*Reports it, that is, under the curious title,

”Fish Fossil Has Oldest Known Face, May Influence Evolution“

Influence evolution? Baby, if they found it back then, it IS evolution. Unless, of course, you mean Evolution, the Religion. In other words, the fish may shake up your dogmatics a bit, but whose problem is that, besides yours, at this point?

Fish guy, yer gettin’ ta be a rabbit with me.

Comments
Ribbit
All this about Ribbits is well understood but considered trivial. We may get a million different types of Ribbits but no new complex capabilities. Different colors and sizes but no new body plans. Just a lot of diversity. Now if one of these lines started to produce some very unusual capabilities and altered body plans then we might sit up and pay attention. Meyer and the ID folks have been saying that this probably never happened. It might have but we have yet to see the examples. Meyer also gives good reasons why it probably never happened. Not proof of anything specific but supportive that another approach may be at the heart of life changes in the last 600 billion years.jerry
October 2, 2013
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Liz:
OK, here is the principle. Let’s say you start of with one kind of organism. We’ll call it a Ribbit. The Ribbit population splits into two for some reason – perhaps half of it gets stranded on an island – and so you get two non-interbreeding populations of Ribbits. We call these two species of Ribbits. We’ll call one lot Ribbit Islandia and the other lot Ribbit Mainlandia. After a while each species of Ribbit also subdivides, so we have four kinds of Ribbits. Ribbit Islandia Major and Ribbit Islandia Minor, and Ribbit Mainlandia Carnivore and Ribbit Mainlandia Omnivore. Then those subdivide as wall, so we have Ribbit Islandia Major Bigteeth and Ribbit Islandia Major Sharpteeth, Ribbit Islandia Major Bigfoot and Ribbit Islandia Major Smallfoot, Ribbit Mainlandia Carnivore Fluffy, Ribbit Mainlandia Carnivore Smooth, Ribbit Mainlandia Omnivore Hairy and Ribbit Mainlandia Ominivore Bald. So what was two species of Ribbit, Islandia and Mainlandia, now needs another name. So a taxonomist arriving late on the scene will declare Ribbit a “Kingdom”, Islandia and Mainlandia, “phyla”, Major, Minor, Omnivore and Carnivore “Classes”, Bigteeth, Sharpteeth, Bigfoot, Smallfoot, Fluffy, Smooth, Hairy, Bald, all “Orders”. And so on.
Just so. :/ I don't think it is the principle that is at issue. We all understand the principle. I'm pretty sure that Meyer understands the principle as well. Rather it is the data that is problematic. If the data were there, we wouldn't be talking about "Ribbits," now would we? Straight question: Is disparity apparent in the fossil record or not? It seems to me that you are avoiding this question/issue by appealing to what is not in evidence instead of addressing what is. Persisting in this makes it look like you are deliberately creating a smoke screen.Phinehas
October 2, 2013
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Hi Jerry, Your post above is what I've been trying to infer for quite some time, asking Elizabeth to provide an example of the stepwise evolution of even one Cambrian animal, from the fossils available. The reason I ask is that I don't believe there exists such a record and therefore I don't see how or why Meyer would base his argument on the 'common descent' of such a creature, especially when it can't be observed. It's as you say; and argument about the mechanisms.PeterJ
October 2, 2013
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What I’m saying is that Meyer’s disparity-diversity argument doesn’t work.
Of course it does. It is a clear reading of the data. There are various organisms in the Cambrian. They can be grouped by those with different sets of body plans. Group 1 are all those organisms that have a specific body plan, Group 2 are all those organisms that have a different but specific body plan, etc. No one has figured out a way how two different plans could arise from a common ancestor let alone about 30. No one has observed a new body plan arising since the Cambrian from another body plan. The term to indicate the presence of these different body plans is called disparity or a major difference between two different organisms because of very different body plans. That has been a traditional use of the term. Within a body plan we have zillions of instances of small variations in this body plan once the original body plan arrived. This is called diversity or represents relatively small differences. These are clear uses of these terms and Meyer uses them as have others before him. The question is how did these organisms with different body plans arise. There is nothing in the fossil record to indicate that there were predecessors that could lead to the various body plans. I believe there may have been a sponge prior to the Cambrian but there is nothing to indicate how a sponge could morph into the various body plans. This is not something Meyer has made up as he quotes scientific reference after scientific reference. Including James Valentine who has spent more time on this topic than anyone. The whole thrust of the book is about how could these various body plans or disparity arise. It is less about the variety afterwards except that it is counter to what Darwin would expect. It is only about UCD in the sense that it also gets questioned as there is no clear path from a LUCA to the various body plans. But the book is mainly about a possible mechanism. To say otherwise is disingenuous at best.jerry
October 2, 2013
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KF: the spin is purely in your imagination. What I'm saying is that Meyer's disparity-diversity argument doesn't work. Sure, there are still lots of unsolved puzzles in the Cambrian and Ediacaran, but the disparity-diversity thing is, dare I say it, a red herring.Elizabeth B Liddle
October 2, 2013
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PS: Let us just say that from Darwin on, theorists have had very good reason to see that on incrementalist evolutionary models, the expectation would be of gradual emergence of wider and wider diversity ranging up to body plan level. I repeat, the credible genetic increment of FSCO/I for a body plan is on simple calcs backed up by observed forms, 10 - 100+ mn bits. This neglects further epigenetic info that actually makes new cell types into body plans. The notion presented above that phyla would emerge rapidly, is not credible save to the eye of a priori materialist faith building an after the fact ad hoc explanation.kairosfocus
October 2, 2013
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EL: More spinning away. The fact is, the Cambrian fossils for dozens of phyla and subphyla, require explanation of origin of body plans requiring 10 - 100+ Mn bits of genetic info for cell types, plus epigenetics which is where the actual body plan seems to come from. The vast majority of Cambrian forms have just no plausible fossil antecedents, INCLUDING the Ediacaran, as is documented in sufficient detail by the author you are trashing, in the very book you are trashing. your refusal to see that the superposition of a hypothetical branching tree pattern on a situation where taxa will be based on OBSERVED forms, in a context where the legendary root species are consistently missing will mean that loops will cut above imagined root nodes -- the very multiple entry points that you have tried to decry, does not change the cogency of that logic. I simply repeat the challenge: demonstrate, preferably from a unicellular root, OBSERVED origin of a phylum of the Cambrian from actual fossil forms. I confidently say this has not been done after 150 years of scouring the world, 250,000 + fossil species, millions of collected specimens and billions of others observed in the ground. (On this last, let me just point out that Barbados is a fossil coral limestone island, with square miles of fossils.) KFkairosfocus
October 2, 2013
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EL: let’s notice the weasel words for what they are. You are accusing of or closely associating what you disagree with, with fraud in a context where there is no good reason for so grave a charge. There is a very reasonable explanation for the main features of Meyer’s text and diagrams that makes the figures reasonable, apart from a typo that appears in two diags from what I have seen. Evidently you refuse to accept that darwinist theories will lead to incrementally increasing stem and crown diversity across time, leading to diversity accumulating into disparity.
I do not dispute, as I have said, clearly, that "darwinist theories will lead to incrementally increasing stem and crown diversity across time". What I do dispute is that this will lead to increasing "disparity" if "disparity" is defined as the number of "higher" taxa". That would be a simple contradiction in terms. "Higher" taxa must precede "lower" according to the theory. You can't get subdivisions of a set before you have the set.
...it is natural that unobserved hypothetical ancestral species will not appear in the categories that cluster species based on wider and wider in common characteristics.
Traits possessed by "unobserved hypothetical ancestral" populations will appear in later clusters. That's why the ancestral population is hypothesised.
Consequently on the assumed branching tree origins, we will see taxonomic loops that cut across multiple branches coming in.
This is just incoherent.
Going out, further developments of more derived species would lead to multiple branches leading out.
Of course. So higher taxonomic categories, like "phyla" will precede the sub groups such as classes and genera. And as branches go extinct, as time goes by the number of phyla will reduce, but the number of sub groups on the remaining branches increase. Just as we observe.Elizabeth B Liddle
October 2, 2013
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KF:
PPPS: Also, we must never let this slip our notice, that for 150 years the fossil patterns have shown sudden onset phylum and subphylum level biodiversity at the Cambrian.
Indeed, although "sudden" is a relative term. It didn't happen overnight.
The Ediacaran fauna shows a similar bang onset of broad diversity, and there is no good case that they are precursors to the Cambrian diversity.
But there is a good case that some Ediacaran groups are ancestral to Cambrian groups, and indeed to all that came later.
Both conventional NDT and punc eek will expect much lower level diversity accumulating to the radical architectural differences of phylum and sub phylum level.
No. What "conventional NDT and punc eek will expect" is a fractal, which is what we observe. We expect lower diversity after a major extinction event, followed by a re-radiation. Something like this sketch. I also recommend this paper by Charles F Marshall (cited by Meyer): Explaining the Cambrian "Explosion" of Animals (pdf) It lays out both the problems and some (but not all) of the solutions, clearly and dispassionately.Elizabeth B Liddle
October 2, 2013
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F/N: Onlookers, I need to link that point again to document the conspiracy theories, as it is the context of all that appears above. And BTW, I think part of what is going on is that a lot of what Meyer says with meticulous research to back it up, with cites and carefully reasoned narrative is exactly the framework of facts, reasoning and inferences EL has been ducking, dodging, mischaracterising and deflecting at and around UD for years. We se the underlying Dawkins pattern, if you disagree with our partlyline, you are ignorant, stupid, insane or wicked. KFkairosfocus
October 2, 2013
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EL: let's notice the weasel words for what they are. You are accusing of or closely associating what you disagree with, with fraud in a context where there is no good reason for so grave a charge. There is a very reasonable explanation for the main features of Meyer's text and diagrams that makes the figures reasonable, apart from a typo that appears in two diags from what I have seen. Evidently you refuse to accept that darwinist theories will lead to incrementally increasing stem and crown diversity across time, leading to diversity accumulating into disparity. That is what Darwin taught, as Meyer cited and as has been clipped above, and it is a reasonable inference on punc eq also. But when taxonomy is cleared of ideologically loaded a prioris and is based on actually observed populations and characteristics [living or fossil], it is natural that unobserved hypothetical ancestral species will not appear in the categories that cluster species based on wider and wider in common characteristics. Consequently on the assumed branching tree origins, we will see taxonomic loops that cut across multiple branches coming in. Going out, further developments of more derived species would lead to multiple branches leading out. So, the logic of matching the branching tree model to the constraint of taxonomy on observed forms accounts for the features you are so desperate to associate with loaded terms like fraud. That contrast speaks volumes and not in your favour, for the point has been repeatedly highlighted to you without cogent response on your part. This leaves us to conclude that your interest here is exactly what has been shown by what you host and seek to justify at your blog: grotesque conspiracy theories designed to poison the atmosphere. KFkairosfocus
October 2, 2013
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PPPS: Also, we must never let this slip our notice, that for 150 years the fossil patterns have shown sudden onset phylum and subphylum level biodiversity at the Cambrian. The Ediacaran fauna shows a similar bang onset of broad diversity, and there is no good case that they are precursors to the Cambrian diversity. Both conventional NDT and punc eek will expect much lower level diversity accumulating to the radical architectural differences of phylum and sub phylum level. P4S: This is one case where we really do need to read the book, to get a flavour for the careful research and obvious experience of teaching fairly technical materials at introductory level that have gone into it. That such a book had to be brought out as a bridge building science informed worldviews work by a publisher that is relatively immune to pressure tactics on sci textbooks etc, speaks volumes about the known censorship tactics of our day. Or, are we so soon conveniently forgetting the obvious power moves played against Springer Verlag over a conference compendium?kairosfocus
October 2, 2013
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KF, I have addressed that repeatedly. It was the entire point of my original post. PeterJ: Yes, there are examples in the fossil record of step by step changes, including within the Cambrian itself. But the organisms right at a node itself are unlikely to be found because they are necessarily far less numerous. The way that phylogenetic inference works is that a tree is fitted to a distribution of inherited "characters" of known organisms. The tree that is fitted to the Cambrian is not, contrary to Meyer's contention, in contradiction to what is expected under Darwinian common descent with modification. Meyer's argument rests equivocation with the concept of taxonomic categories. Optimus: I am certainly highly critical of Meyer but my argument is not "ad hominem"; unlike arguments made here by Mung and KF against me, namely, that my argument must be wrong because I am a bad person, my argument is not that Meyer's argument must be wrong because he is dishonest and/or stupid. My argument is that Meyer's argument is fallacious on the grounds I have given (equivocation) and that therefore, because he is not stupid, I suspect him of dishonesty. I certainly consider that the diagrams that he has in his book are verging on fraudulent. They certainly do not represent what he claims they do.Elizabeth B Liddle
October 2, 2013
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PPS: If you will read DD chs 6 and 7 you will see why punc eq failed as a theory of body plan level origins, after its splash introduction, as the issue of where the variations came from to make the new species through geographic isolation came about. Turns out the punc eq model depends strongly on CV + DRS --> IDWUM, as I have discussed above. In short the punc eq model of speciation is not a good model of novel body plan origin.kairosfocus
October 2, 2013
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PS: You will observe how as well the challenge to actually document evolutionary origin of a phylum from a root species per observations congruent with blind watchmaker assumptions or models has gone conspicuously un-answered. It remains the case that the only empirically warranted mechanism capable of causing FSCO/I is design.kairosfocus
October 2, 2013
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Collin, Please scroll up. You will see that EL is repeatedly refusing to address on the merits the framework laid out by Darwin et al (to include the punc eq theory of the 70's - 80's) that shows why per evolutionary materialist approaches we will have increasing diversity across time, and why an insistence on classification schemes that are rooted in observed populations will not include consistently hypothetical but not observed ancestral species. In that context, the insistence to trash Meyer as incompetent needs to be understood in a wider context of an obvious and uncivil ideological agenda. One that unfortunately needs to be sufficiently highlighted to burn through the filters and deflection tactics; for much the same reason why advertisers repeat their messages. KFkairosfocus
October 2, 2013
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To make things clearer; I don't see why Meyer would base his whole argument on something that hasn't been shown to have ever existed(common ancestor). Why would he? It's all about mechanisms, surely.PeterJ
October 1, 2013
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I'm still waiting for an answer to me question in #176, reffering to "while the set of shared features is inferred to have been possessed by the common ancestor.” Again, Elizabeth. Can you you give me an example of the 'common ancestor(s)' that your implying exist in the fossil record, concering the Cambrain fossils of course? The reason I ask Elizabeth is this; if Meyer is making an argument against 'common descent', as you are trying to assert, then surely there must exist fossils that show this taking place in a step by step fashion. Or is it the case that this is not what his main argument is about at all?PeterJ
October 1, 2013
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@ EL You wrote:
He isn’t stupid. I think it’s worse than that.
In my view, Darwin’s Doubt is a masterpiece of equivocation, and I think Meyer is smart enough to know this. That is why I express my disapproval in my post – not because I am “prejudiced” against his case (it would be cool if true) but because I don’t think he is being honest. I think the book is a piece of polemic disguised as reasonable argument, and the trick used is the oldest one in the book – equivocation with terms.
My point is simply the point I made: that Meyer’s book is not a scientific book, albeit one dealing with “scientific topics”, because Meyer’[sic] lacks the knowledge and understanding of palaeontology to write a scientific books[sic].
Either he is so convinced of his own priors that he has missed his own error, or he knows it’s there, but wanted to write a book that encouraged people to think that the Cambrian Explosion is evidence for God.
You're quite a maelstrom of ad hominem, aren't you? First, you indicate that Meyer isn't stupid - he's just devious, dishonestly making up stories about the Cambrian to make it into a boogeyman for Darwinian theory. Second, you indicate that maybe he is stupid after all - that is, of course, generally what is meant by 'lacks the relevant knowledge and understanding'. I'm rather confused about your standpoint, but I suppose confusion is the handmaiden of contradiction. What really blew me away is your knee-jerk inclination to dismiss an entire book with some seventy pages of endnotes and references as a lame attempt to foster belief in God. Why are you in such a rush to drag theology into so many of these discussions? Do the potential theistic implications of ID make you uncomfortable? What might that imply about your own motivations for opposing ID so stridently (and ineptly)?Optimus
October 1, 2013
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Meyer argues that under Common Descent we should see small morphological distances between lineages that become larger over time, as each lineage diversifies down separate lineages. Correct.
Indeed.
He then argues that we don’t see this. Wrong. He bases his assertion that we don’t see it on the fact that “phyla” divisions, come before “lower taxa” such as “families” or “genera” in the fossil record. Correct. He then characterises phyla as groups separated by a “large morphological distance”, and thus argues that because phyla came before genera, then large distances came before small, in contradiction to the expectation under Common Descent.
It seems that you're attempting to argue that the morphological differences evident in the Cambrian fauna aren't really of any significance, at least not enough contradict the standard Darwinian picture of development. Is that correct? If so, your argument is a rather strange one. If, indeed, the morphological differences apparent in the Cambrian fauna are small, then why on earth would Darwin and subsequent scientists have perceived the Cambrian as a problem in need of explanation? Why have there been so many artifact hypotheses? What is it exactly that persons working within the Neo-Darwinian framework are trying to explain? That there was a relatively abrupt appearance of organisms that weren't terribly different from one another? There was an excellent article on ENV that came out in the same month as Darwin's Doubt. It highlights some major points of intersection between Meyer's book and Erwin and Valentine's book on the Cambrian explosion. Here's the link: http://www.evolutionnews.org/2013/06/erwin_valentine_cambrian_explosion073671.html There are a few statements from the piece that are particularly relevant to your position:
To be sure, all pairs of crown phyla had common ancestors; as far as we know, however, none of those bilaterian LCAs had features that would cause them to be diagnosed as members of living phyla, although that could be the case in a few instances. In other words, the morphological distances -- gaps -- between body plans of crown phyla were present when body fossils first appeared during the explosion and have been with us ever since. The morphological disparity is so great between most phyla that the homologous reference points or landmarks required for quantitative studies of morphology are absent. (p. 340) (Emphasis mine)
Here's another:
Morphologic evolution is commonly depicted with lineages more or less gradually diverging from their common ancestor. New features arise along the evolving lineages ... Gould (1989, 38) characterized this pattern as the "cone of increasing diversity," but neither the Cambrian nor the living marine fauna display this pattern. (pp. 339-340) (Emphasis from article)
Now this is precisely the argument that Meyer makes. He's not fabricating or equivocating anything. The distinction between the theoretical expectation of Darwinism and the fossil data for morphological development is real. It cannot simply be defined away. J.Y. Chen also described the fossil pattern as being in opposition to Darwinian expectations (see Darwin's Doubt pg. 50-52). You write:
Bottom line: Common Descent predicts that small differences will precede diversification. This is what we observe in the fossil record. What we call things is irrelevant to the straightforward match between prediction and observation.
The Cambrian explosion begs to differ.Optimus
October 1, 2013
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Elizabeth B Liddle:
Meyer is defining “disparity” as “lots of higher taxa”.
Elizabeth, how do you reconcile the differences between your characterization of what Meyer wrote and what Meyer actually wrote?
In its technical sense, disparity refers to the major differences in form that separate the higher-level taxonomic categories such as phyla, classes and orders. In contrast, the term diversity refers to minor differences among organisms classified as different genera or species. Put another way, disparity refers to life's basic themes; diversity refers to the variations on those themes. - Meyer (p. 39)
Mung
October 1, 2013
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EL:
So I’m saying yes, there was more disparity earliery, when, counted as number of phyla (more than now, as some when extinct) and yes, those phyla each gave rise to radically different body plans.
Just. Priceless.Mung
October 1, 2013
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Elizabeth B Liddle:
Meyer is defining “disparity” as “lots of higher taxa”.
Is this another alleged quote of Meyer that isn't a quote of Meyer? Quote-facturing again? Where in the book does Meyer define disparity as “lots of higher taxa”? I understand you have it on Kindle, so just get us in the general vicinity please. Start with the chapter and at least some sort of actual quote. If you have one.Mung
October 1, 2013
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This book has presented four separate scientific critiques demonstrating the inadequacy of the neo-Darwinian mechanism, the mechanism that Dawkins assumes can produce the appearance of design without intelligent guidance. It has shown that the neo-Darwinian mechanism fails to account for the orign of genetic information because: (1) it has no means of efficiently searching combinatorial sequence space for functional genes and proteins and, consequently, (2) it requires unrealistically long waiting times to generate even a single new gene or protein. It has also shown that the mechanism cannot produce new body plans because: (3) early acting mutations, the only kind capable of generating large-scale changes, are also invariably deleterious, and (4) genetic mutations cannot, in any case, generate the epigenetic information necessary to build a body plan. - Meyer (p. 411)
I am truly attempting to understand your logic Elizabeth. It took me a while to understand that you think Meyer is arguing for special creation. Now my question is, since Meyer claims to be disputing the adequacy of the neo-darwinian mechanism, and he does so repeatedly in the book, from cover to cover, including explicitly in Chapter 2 and Chapter 7 (as I have no documented), how does it follow that he is arguing against common descent? What's your reasoning? Are you saying that you can't separate the two?Mung
October 1, 2013
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Elizabeth Liddle:
The early part of the book is devoted to making the argument that there is a problem (“early disparity”) to solve – that what we observe isn’t what Darwin expected, and therefore Darwin’s mechanism can’t explain it.
That's not how I would have put it, but at least you're beginning to see the light.Mung
October 1, 2013
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Elizabeth Liddle:
Mung, I just checked, and you are in fact incorrect. Meyer does use the term common descent...
What am I "in fact" incorrect about? From your post it's almost impossible to discern what claim you think I made that I am incorrect about. Please clarify. Now, as for this nonsense about Meyer arguing against common descent. How do explain the first diagram in your OP at TSZ? How do you interpret that diagram in light of your belief about what Meyer is arguing against? Was each class specially created and was each genus specially created? Is that what you think Meyer is saying? To me they show common descent. I'd like to know how that fits your narrative.Mung
October 1, 2013
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Meyer is saying that "disparity precedes diversity" in the fossil record, and that this is a problem for the Darwinian account, which predicts that populations should diverge a little before they diverge a lot. Meyer is defining "disparity" as "lots of higher taxa". Defined this way, then disparity does precede diversity. But it doesn't contradict the Darwinian prediction (not in fact a "prediction" at all, but a conclusion from evidence, but let's call it a prediction for now) because at the time when there were lots of different phyla, the phyla weren't as different from each other as they later became. And indeed, Darwinian theory predicts that phyla will be extremely similar when they first diverge - as similar as two species are today. But Meyer defines "phyla" as groups that are "morphologically distant" - have very different forms. And so he's taking one definition of phyla ("very different forms") and another definition of phyla ("branches that diverged a very long time ago) to argue that "very different forms" existed before more similar forms. There is a sense in which he has a point. The taxonomic category "phylum" does describe organisms with very different body plans. But that doesn't mean even those very different body plans were so radically different when they first diverged. If you take two organisms, very similar, both with two openings, and both developing "anus first", but one lot tends to develop into an organism with a simple nerve that grows out from the middle in two directions make two ends, and another organism in which the nerve grows out from the middle in three, four or five. All these organisms look pretty similar. But one lineage becomes starfish, and the other becomes us. Vastly different body-plans, but, at the time of bifurcation, not radically different. But because what came next was so strongly constrained by what came before, that small difference in the number of ways the nerve grew out from the middle because the difference between a lineage with a single spinal chord and bilateral symmetry, and, eventually, a brain, and a lineage with radial symmetry, and no brain. So I'm saying yes, there was more disparity earliery, when, counted as number of phyla (more than now, as some when extinct) and yes, those phyla each gave rise to radically different body plans. But I'm saying that what Meyer glosses over is evidence that they weren't so different at the beginning - just as Common Descent predicts. And I'm also saying that we can see that Meyer is glossing over this, because when he draws (or commissions drawings) to illustrate the concept, he gets it completely wrong, circling as "phyla" groups that have no node.Elizabeth B Liddle
October 1, 2013
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Liz:
The early part of the book is devoted to making the argument that there is a problem (“early disparity”) to solve – that what we observe isn’t what Darwin expected, and therefore Darwin’s mechanism can’t explain it. The problem is that there isn’t a problem.
I can't tell whether you are saying that there is no early disparity in the fossil record or that there is, but it isn't a problem. Can you elucidate?Phinehas
October 1, 2013
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Liz:
But the mechanism of change is irrelevant to his argument in Chapter two. It is common descent of diverging lineages he is talking about, and my point holds.
Especially since Mung has provided actual quotes from the book to back up his claims about the focus of Meyer's discussion, it is difficult to take mere gainsaying seriously without contrary evidence. Care to provide some?Phinehas
October 1, 2013
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Mung
>Yet that’s exactly what it’s about. The entire book is about proposed mechanisms to account for the early disparity in form (morphology). How anyone could read the book and come away with the exact opposite conclusion is just astounding.
Because, Mung, his argument that there is even a problem to solve falls at that very fence. The early part of the book is devoted to making the argument that there is a problem ("early disparity") to solve - that what we observe isn't what Darwin expected, and therefore Darwin's mechanism can't explain it. The problem is that there isn't a problem. "Early disparity" is not what he says it is, and it only looks like he says it is because he mislabels, both in his text and in his diagrams, what a "phylum" consist of, and therefore his definition of "disparity" falls apart.Elizabeth B Liddle
October 1, 2013
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