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Re: Segmentation and Vertebrate Origins

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  • Cliff Lundberg
    ... Let s just talk about the evidence that leads to my model. If you accept that, the rest is easy. I refer to the pattern of reduction in the number of
    Message 1 of 3 , Aug 10, 2001
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      Stephen E. Jones wrote:

      >But I am not claiming that I *cannot* believe something. On the
      >contrary I have said I *could* accept Cliff's explanation, and in fact I
      >was (and still am) favourably disposed towards it. What I wanted from
      >Cliff was more *details*, but these were never forthcoming, except in
      >dribs and drabs. My `baloney detector' swings into action whenever I
      >see someone not being open and straightforward in presentation of
      >their evidence and arguments.

      Let's just talk about the evidence that leads to my model. If you accept
      that, the rest is easy. I refer to the pattern of reduction in the number of
      skeletal parts and loss of symmetry between parts that has been observed
      in fossil series showing evolutionary trends. By 'fossil series' I don't mean
      arbitrary arrangements of animals based on a general theory of increasing
      complexity; I mean fossils showing evolution among indisputably related
      animals; the horse series is the classic. (This series shows reduction in
      that digits are lost.)

      This is not my idea or observation. This was accepted as a general principle
      in paleontology early in the 20th Century. Since then it has not been refuted,
      but it has been abandoned. In the era of the modern synthesis, scientists
      were all expected to support the general theory of gradually increasing
      complexity in evolution, and this anomalous generalization offered nothing
      in support of that.

      As I have mentioned, Gould grumps a bit about this generalization in
      Paleobiology 6:1 (1980): it lacks an explanation, it is not deducible from
      probability, consequences cannot be deduced through it.

      But Gould is wrong. This pattern can be explained, it is deducible from
      probability, and it does serve as a basis for predictions. First, the
      pattern must be taken seriously; we must recognize that the implication
      is that earlier, more primitive organisms in lineages of segmented
      organisms had more skeletal parts and these parts were more
      symmetrical. Further, the implication is that future descendants
      will have fewer skeletal parts and less symmetry among these
      parts. This is simply extrapolating from a clear pattern; but it is
      rather unthinkable for the 20th Century evolutionist, because it
      doesn't support the picture of increasing complexity in every
      sense; even in this limited sense of number-of-skeletal-parts, there
      must be discomfort among Darwinians at this unexpected trend
      among segmented organisms such as vertebrates.

      There are many supposed evolutionary transformations that do not
      fit this pattern at all, such as the evolution of land vertebrates from
      Coelacanths, or snakes from reptiles with fewer segments. And the
      ultimate end, with segments down to a bare minimum, and no parts
      free to be adapted to new functions, is really unthinkable. But the
      facts are there, we have to recognize the trend.

      Deduction from probablility is easy, once the pattern is understood
      and accepted. Random mutation, acting upon an array of symmetrical
      elements, should produce loss of elements and distortion among
      formerly symmetrical elements. Adding new segments, complete
      with infrastructure and functional enough to be advantageous, and
      symmetrical with existing segments, seems a much more difficult
      thing for random mutation to accomplish.

      A formative process must be postulated, during which a duplicative
      process like Siamese-twinning formed many-segmented colonial
      organisms, which subsequently consolidated into the integrated
      organisms which form the varieties of segmented organisms.

      Why couldn't such a duplicative process add segments within a
      segmented organism? Well, in biology anything *could* happen, but
      we deal with what is probable. Duplication of the whole body is a
      feasible and observable phenomenon; but having one Siamese-twin
      be so partially formed that it amounted to but one skeletal segment,
      perfectly positioned, is unlikely.

      The Cambrian Explosion does not mark the advent of DNA, or cells,
      or hard parts. It is an explosion of experimentation at the level of
      gross skeletal morphology, and the formation of segmentation is
      the gimmick that sets it off. I would think a progressive creationist
      would mark this event as one of divine-intervention stature.

      >What Cliff seems to want me to be is personally *credulous*, so that I
      >just accept his vague model on *his* say-so, and wave away any
      >inconvenient facts (like the almost perfect morphological and temporal
      >correspondence between reptilian and mammalian jaw-ear bones), with
      >vague answers like it being the result of "common ancestry" with some
      >unknown "progenitor" ~300 million years earlier!

      At www.cab.com/segment/progenit.html I describe the model in detail,
      depicting the formation of segmented progenitors in clear pictures. I don't
      see how this can be called a vague model.

      The correspondence among reptilian and mammalian skull bones is
      obvious, and it proves common ancestry. I prefer to think one did not
      evolve from the other, because of the unlikelihood of the more complex
      mammalian hearing bones being elaborated from the reptilian format,
      and because my general model tends to make me accept that there
      were important unknown progenitors at various levels. The fossils
      are the evidence, but we are free to interpret them, we can't just say
      the fossils in themselves are the complete history, if we could only
      arrange them in just the right order.

      >"This regular absence of transitional forms is not confined to mammals, but is

      >an almost universal phenomenon, as has long been noted by paleontologists. It
      >is true of almost all orders of all classes of animals, both vertebrate and
      >invertebrate. A fortiori, it is also true of the classes, themselves, and of
      >the
      >major animal phyla, and it is apparently also true of analogous categories of
      >plants. Among genera and species some apparent regularity of absence of
      >transitional types is clearly a taxonomic artifact: artificial divisions
      >between
      >taxonomic units are for practical reasons established where random gaps exist.

      >This does not adequately explain the systematic occurrence of the gaps
      >between larger units. In the cases of the gaps that are artifacts, the
      >effect of
      >discovery has been to reveal their random nature and has tended to fill in now

      >one, now another-now from the ancestral, and now from the descendent side.
      >In most cases discoveries relating to the major breaks have produced a more
      >or less tenuous extension backward of the descendent groups, leaving the
      >probable contact with the ancestry a sharp boundary. None of these large
      >breaks has actually been filled by real, continuous sequences of fossils,
      >although many of them can be exactly located and the transitions described by
      >inference from the improved record on both sides. In addition to the fact that

      >they exist, there are other more or less systematic features of these
      >discontinuities of record that call for attention and require explanation."
      >(Simpson G.G., "Tempo and Mode in Evolution," [1944]

      The lack of transitional forms is addressed by postulating unknown common
      ancestors, pushing the timing of divergences further back in time. My model
      makes this easier to accept, because if skeletal evolution is proceeding only
      by reduction and distortion of a pre-existing complex of segments, then
      parallelism is far more feasible than if skeletal evolution were elaborative
      in the sense of the number of segments. Where evolution is limited, parallelism
      is more feasible, than when evolution is utterly open-ended.

      Mammals can be similar to reptiles without having to have diverged from
      reptiles just at the point where we first see mammals in the fossils. We can
      postulate unknown pre-existing mammals, in the trees or wherever; we know
      the fossils are a sketchy 'record', so why not do this, rather than having to
      imagine crunching jaw-bones gradually becoming part of the delicate
      hearing-bone chain? Then there are questions about fur, and lactation, and
      brain size; big things, to be glossed over so readily.

      --
      Cliff Lundberg ~ San Francisco ~ 415-648-0208 ~ cliff@...
    • Stephen E. Jones
      Group On Fri, 10 Aug 2001 01:29:52 -0700, Cliff Lundberg wrote: I apologise to Cliff for this being two months late! ... CL Let s just talk about the evidence
      Message 2 of 3 , Oct 8, 2001
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        Group

        On Fri, 10 Aug 2001 01:29:52 -0700, Cliff Lundberg wrote:

        I apologise to Cliff for this being two months late!

        >SJ>But I am not claiming that I *cannot* believe something. On the
        >>contrary I have said I *could* accept Cliff's explanation, and in fact I
        >>was (and still am) favourably disposed towards it. What I wanted from
        >>Cliff was more *details*, but these were never forthcoming, except in
        >>dribs and drabs. My `baloney detector' swings into action whenever I
        >>see someone not being open and straightforward in presentation of
        >>their evidence and arguments.

        CL>Let's just talk about the evidence that leads to my model. If you accept
        >that, the rest is easy. I refer to the pattern of reduction in the number of
        >skeletal parts and loss of symmetry between parts that has been observed
        >in fossil series showing evolutionary trends.

        Who would disagree that there has been "reduction in the number of
        skeletal parts and loss of symmetry between parts"? I am sure even the
        ICR would agree with this. The thing to be explained is not "reduction"
        but how what is later reduced came to be built up in the first place.

        It reminds me of Spetner's observation that mutations which lose
        information cannot be the explanation of the original build-up of that
        information:

        "Whoever thinks macroevolution can be made by mutations that
        lose information is like the merchant who lost a little money on
        every sale but thought he could make it up on volume." (Spetner
        L.M., "Not by Chance!: Shattering the Modern Theory of
        Evolution," Judaica Press: New York, 1997 revised, p.160)

        CL>By 'fossil series' I don't mean
        >arbitrary arrangements of animals based on a general theory of increasing
        >complexity; I mean fossils showing evolution among indisputably related
        >animals; the horse series is the classic. (This series shows reduction in
        >that digits are lost.)

        Again, I have no problem with the "horse [or any] series" that "shows
        reduction in ... digits" (or anything for that matter).

        I agree with Dawkins in that "what I mainly want a theory ... to ... explain
        complex, well-designed mechanisms like hearts, hands, eyes and
        echolocation":

        "As I said at the beginning of this chapter, what I mainly want a
        theory of evolution to do is explain complex, well-designed
        mechanisms like hearts, hands, eyes and echolocation." (Dawkins
        R., "The Blind Watchmaker," [1986], Penguin: London, 1991
        reprint, p.265)

        To "explain the sort of complex multidimensional adaptation that ... seems
        to demand a shaping agent at least as powerful as a deity:

        ".... to explain the sort of complex multidimensional adaptation that
        I find interesting, the 'Paley's watch', or 'Organs of extreme
        Perfection and Complication', kind of adaptation that seems to
        demand a shaping agent at least as powerful as a deity." (Dawkins
        R., "The Extended Phenotype: The Long Reach of the Gene,"
        [1982], Oxford University Press: Oxford UK, 1983, p.108).

        I am not as much interested in what Dawkins calls the "boring parts of
        evolution" which "cannot be responsible for ... change in the direction of
        building up improved devices for survival like eyes, ears, elbow joints,
        and echo-ranging devices":

        "...but they cannot be responsible for adaptive evolutionary change,
        that is for change in the direction of building up improved devices
        for survival like eyes, ears elbow joints, and echo-ranging devices.
        Of course, large quantities of evolutionary change may be non-
        adaptive, in which case these alternative theories may well be
        important in parts of evolution, but only in the boring parts of
        evolution, not the parts concerned with what is special about life as
        opposed to non-life." (Dawkins R., "The Blind Watchmaker," 1991,
        p.303)

        CL>This is not my idea or observation. This was accepted as a general principle
        >in paleontology early in the 20th Century.

        OK. I will be happy to listen if Cliff explains his theory, but I must say I am
        not going to pursue him in this matter. It might be interesting to Cliff, but it
        sounds to me like one of what Dawkins calls above "the boring parts of
        evolution".

        CL>Since then it has not been refuted, but it has been abandoned.

        Perhaps it did not even *need* to be "refuted"? That is, it was true but
        relatively unimportant?

        Given the competitive nature of science, I would be surprised if there
        really was an important naturalistic explanation in the past that "has not
        been refuted, but ... has been abandoned" which some bright, young,
        ambitious paleontology graduate student did not pick up an run with it.

        CL>In the era of the modern synthesis, scientists
        >were all expected to support the general theory of gradually increasing
        >complexity in evolution, and this anomalous generalization offered nothing
        >in support of that.

        I would expect that was because "gradually increasing complexity" is the
        major problem to be explained, when reduction of that "complexity" is not.

        CL>As I have mentioned, Gould grumps a bit about this generalization in
        >Paleobiology 6:1 (1980): it lacks an explanation, it is not deducible from
        >probability, consequences cannot be deduced through it.

        If Cliff will give me the full article reference, including its title and page
        numbers I will try to get it so I can try to understand what Cliff is driving
        at. I seem to remember asking Cliff for this before and I apologise if he had
        already given it to me in the past.

        CL>First, the
        >pattern must be taken seriously; we must recognize that the implication
        >is that earlier, more primitive organisms in lineages of segmented
        >organisms had more skeletal parts and these parts were more
        >symmetrical.

        If by "skeletal parts" Cliff means *bones*:

        --------------------------------------------------------------------------
        http://m-w.com/cgi-bin/dictionary?book=Dictionary&va=skeletal
        Main Entry: skeletal ... Function: adjective Date: 1854 : of, relating to,
        forming, attached to, or resembling a skeleton ...

        http://m-w.com/cgi-bin/dictionary?book=Dictionary&va=skeleton
        Main Entry: 1skeleton ... Function: noun Etymology: New Latin, from
        Greek, neuter of skeletos dried up; akin to Greek skellein to dry up,
        sklEros hard and perhaps to Old English sceald shallow Date: 1578 1 : a
        usually rigid supportive or protective structure or framework of an
        organism; especially : the bony or more or less cartilaginous framework
        supporting the soft tissues and protecting the internal organs of a
        vertebrate ...
        --------------------------------------------------------------------------

        then "more primitive organisms in lineages of segmented organisms" were
        invertebrates, i.e. boneless.

        CL>Further, the implication is that future descendants will have fewer
        >skeletal parts and less symmetry among these parts.

        Not necessarily. If invertebrates had no "skeletal parts" (i.e. bones) and
        vertebrates were their "future descendants" then the latter had more*
        "skeletal parts".

        CL>This is simply extrapolating from a clear pattern; but it is
        >rather unthinkable for the 20th Century evolutionist, because it
        >doesn't support the picture of increasing complexity in every
        >sense; even in this limited sense of number-of-skeletal-parts, there
        >must be discomfort among Darwinians at this unexpected trend
        >among segmented organisms such as vertebrates.

        I doubt that "Darwinians" would find it "unthinkable" or that it would
        cause them any "discomfort". If they are focused mainly on "the picture of
        increasing complexity" it is because that is the main problem to be
        explained. That more complex skeletons can lose "skeletal parts" and hence
        have "less symmetry" is not a major problem to be explained. Darwin's Origin
        of Species even contained sections which dealt with the "Use and Disuse of
        Parts".

        CL>There are many supposed evolutionary transformations that do not
        >fit this pattern at all, such as the evolution of land vertebrates from
        >Coelacanths

        What makes Cliff think that "land vertebrates" arose "from Coelacanths"?
        AFAIK no leading evolutionist makes that claim.

        CL>or snakes from reptiles with fewer segments.

        Indeed! Why does Cliff call "snakes from reptiles" a "supposed evolutionary
        transformation"? Is he claiming that "snakes" did not arise "from reptiles
        with fewer segments"? If so, what is his *evidence*?

        CL>And the ultimate end, with segments down to a bare minimum, and no
        >parts free to be adapted to new functions, is really unthinkable.

        This sounds to me like Cliff is trying to `hype' his theory. I doubt that
        anyone has a problem thinking of "segments down to a bare minimum, and
        no parts free to be adapted to new functions".

        CL>But the facts are there, we have to recognize the trend.

        What there could be disagrement about is Cliff's claim that it is necessarily
        "the ultimate end" and a "trend". What is "a bare minimum" anyway?

        What is Cliff's model's testable prediction? That there is a "trend" in *all*
        lines of organisms towards an "ultimate end" of *one* of every part?

        If so, what is the evidence of this? Some many-segmented organisms like the
        centipedes and millipedes, and snakes for that matter, have remained the same
        for hundreds of millions of years and show no sign of reducing their number of
        segnents.

        CL>Deduction from probablility is easy, once the pattern is understood
        >and accepted. Random mutation, acting upon an array of symmetrical
        >elements, should produce loss of elements and distortion among
        >formerly symmetrical elements.

        Agreed, but only if the "elements" have no selective value. But then so what?

        CL>Adding new segments, complete
        >with infrastructure and functional enough to be advantageous, and
        >symmetrical with existing segments, seems a much more difficult
        >thing for random mutation to accomplish.

        Agreed. In those cases, maybe it was not by *random* mutation? That is,
        it was supernaturally directed?

        CL>A formative process must be postulated, during which a duplicative
        >process like Siamese-twinning formed many-segmented colonial
        >organisms, which subsequently consolidated into the integrated
        >organisms which form the varieties of segmented organisms.

        Has Cliff any actual *evidence* for this "Siamese-twinning" among
        "colonial organisms"?

        Or that "Siamese-twinning" is heritable? i.e. if a male set of Siamese
        twins mates with a female set of Siamese twins that their offspring
        will be a set of siamese twins?

        Siamese-twinning is a post-conception developmental disorder, so how
        could it be inherited?

        Which "colonial organisms" were these exactly anyway?

        CL>Why couldn't such a duplicative process add segments within a
        >segmented organism? Well, in biology anything *could* happen, but
        >we deal with what is probable.

        Even Dawkins accepts that there have been "segments [added] within a
        segmented organism":

        "Stretched DC8 macromutations are mutations that, although they
        may be large in the magnitude of their effects, they turn out not to
        be large in terms of their complexity. The Stretched DC8 is an
        airliner that was made by modifying an earlier airliner, the DC8. It
        is like a DC8, but with an elongated fuselage. It was an
        improvement at least from one point of view, in that it could carry
        more passengers than the original DC8. The stretching is a large
        increase in length, and in that sense is analogous to a
        macromutation. More interestingly, the increase in length is, at first
        sight, a complex one. To elongate the fuselage of an airliner, it is
        not enough just to insert an extra length of cabin tube. You also
        have to elongate countless ducts, cables, air tubes and electric
        wires. You have to put in lots more seats, ashtrays, reading lights,
        12-channel music selectors and fresh-air nozzles. At first sight there
        seems to be much more complexity in a Stretched DC8 than there is
        in an ordinary DC8, but is there really? The answer is no, at least to
        the extent that the 'new' things in the stretched plane are just 'more
        of the same'. (Dawkins R., "The Blind Watchmaker," 1991, pp.234-235)

        CL>Duplication of the whole body is a feasible and observable phenomenon;

        It occurs within humans, i.e. identical twins. But does it happen in other
        taxa? If so, which ones?

        CL>but having one Siamese-twin
        >be so partially formed that it amounted to but one skeletal segment,
        >perfectly positioned, is unlikely.

        Why does Cliff think it needs a "Siamese-twin" to duplicate a "skeletal
        segment"? Duplication of Hox genes are claimed to be able to do it:

        "But there is another crucial aspect in which at least fruit flies,
        frogs, zebra fish, chickens, mice, and humans are similar. Their
        bodies are segmented. In fruit flies, as in other insects, as well as in
        crustaceans such as shrimp and lobsters, the musculature and the
        outer hardened shell also differentiate into series of segmented units
        that resemble the overlapping plates of a suit of armor. In
        vertebrates, the muscles of the trunk and even of the limbs arise as
        segmental units, as do the bones that lie internal to them. The
        development of segmentation in such a diverse array of animals did
        not arise purely by chance in each animal or in the immediate
        ancestor of each animal. One of the biggest ongoing discoveries in
        developmental genetics is that all segmented animals studied to date
        share similar regulatory molecules, which orchestrate the
        development of segmentation. When these molecules were first
        discovered, they were called homeobox genes and referred to as
        Hox genes for short. The abbreviation Hox is still used to designate
        the regulatory genes that are involved in the development of
        segmentation and segmented structures, but the term homeobox
        gene now covers the entire gamut of regulatory genes that are
        fundamental to an organism's development." (Schwartz J.H.,
        "Sudden Origins: Fossils, Genes, and the Emergence of Species,"
        John Wiley & Sons: New York NY, 1999, p.35).

        Interestingly, according to Google, Cliff's "Segmentation and Vertebrate
        Origins" web pages at http://www.cab.com/segment/tablecon.html don't
        seem to contain the words "hox" or "homeobox". If this is in fact the case,
        then it sounds like Cliff is ignoring modern developmental genetic
        explanations in order to push his "Siamese-twinning" explanation?

        CL>The Cambrian Explosion does not mark the advent of DNA, or cells,
        >or hard parts. It is an explosion of experimentation at the level of
        >gross skeletal morphology, and the formation of segmentation is
        >the gimmick that sets it off.

        These were mostly invertebrates, with one or two boneless notachord early
        vertebrates (e.g. Pikaia), so it can hardly be said to be an "explosion ... at
        the level of gross *skeletal* morphology" (my emphasis).

        CL>I would think a progressive creationist
        >would mark this event as one of divine-intervention stature.

        If there is no good naturalistic explanation of a major transition, then I
        would consider it as a candidate for "divine-intervention".

        >SJ>What Cliff seems to want me to be is personally *credulous*, so that I
        >>just accept his vague model on *his* say-so, and wave away any
        >>inconvenient facts (like the almost perfect morphological and temporal
        >>correspondence between reptilian and mammalian jaw-ear bones), with
        >>vague answers like it being the result of "common ancestry" with some
        >>unknown "progenitor" ~300 million years earlier!

        CL>At www.cab.com/segment/progenit.html I describe the model in detail,
        >depicting the formation of segmented progenitors in clear pictures. I don't
        >see how this can be called a vague model.

        What is "vague" about Cliff's "model" is that it has no connection with
        reality, i.e. with the *name* of any *actual* organism as revealed in the
        *fossil record*. There is no *name* of any organism in the above web page.
        There are no footnotes in it referencing the scientific literature.

        Cliff's model seems to be just that-a model-which Cliff has made up off the
        top of his head? I admire Cliff's ability to do it-it probably takes powers
        of imagination of a high order.

        But just imagining theoretical "progenitors", while it is no doubt an
        enjoyable pastime, does not mean that it has any relevance to *what
        actually happened*. To do that, Cliff has to tie his model in with the
        fossil record.

        CL>The correspondence among reptilian and mammalian skull bones is
        >obvious, and it proves common ancestry.

        That two different organisms have a "skull" *at all*, "`proves' common
        ancestry"! But the question is: how *close* was that "correspondence among
        reptilian and mammalian skull bones" and hence how *close* was that "common
        ancestry"?

        If Cliff's theory cannot explain "the perfect morphological correspondence
        between the [jawbones-earbones] conditions in reptiles and in mammals":

        "The important point to notice in these changes is the perfect
        morphological correspondence between the conditions in reptiles
        and in mammals. All the elements that are cartilage-bones in the
        former are so also in the latter: the same is true of the membrane-
        bones and their relative positions correspond exactly. This
        correspondence also extends to minute details. The columella in
        reptiles is frequently pierced by a hole through which the stapedial
        artery passes; this is constant for the stapes of mammals, and is the
        reason why it is called the 'stirrup'. The lateral head vein runs back
        medially to the quadrate in reptiles and to the incus in mammals.
        The facial nerve passes out of the brain case and runs backwards on
        the median side of the quadrate in reptiles and of the incus in
        mammals. The nerve passes above the tympanic cavity on the outer
        side of the stapedial artery and gives off a branch, the chorda
        tympany which runs forwards above the tympanic cavity and then
        down on the median side of the lower jaw elements, articular or
        malleus, in exactly the same way in reptiles and in mammals."
        (deBeer G., "Homology: an unsolved problem," [1971], in Ridley
        M., ed., "Evolution," Oxford Readers, Oxford University Press:
        Oxford UK, 1997, p.217)

        then at best it is not a general theory and at worst it is a false theory.

        CL>I prefer to think one did not
        >evolve from the other, because of the unlikelihood of the more complex
        >mammalian hearing bones being elaborated from the reptilian format,
        >and because my general model tends to make me accept that there
        >were important unknown progenitors at various levels.

        Cliff has hit the nail on the head! That "mammalian hearing bones" arose
        from "the reptilian format" does not explain *why* it happened:

        "Embryology and paleontology provide adequate documentation of
        the `how,' but we would also like more insight into the `why.' In
        particular, why should such a transition occur-especially since the
        single-boned stapedial ear seems to function quite adequately (and,
        at least in some birds, every bit as well as the three-boned
        mammalian ear)?" (Gould S.J., "An Earful of Jaw", "Eight Little
        Piggies: Reflections in Natural History," Jonathan Cape: London,
        1993, p.106)

        "The reptile-mammal jawbones/earbones transition is just the final stage of
        another far-sighted `construction project', namely the mammalian (and
        hence human) ear:

        If the eye is the most complex instance of coordinated
        development, the ear is perhaps the most puzzling, because of the
        extensive way in which existmg structures, originally intended for
        another purpose, were remodelled to detect and analyse sound. ...
        Bear in mind that the ear has a double function: it is both an organ
        for detecting sound and one for preserving balance by analysing the
        movements the body is undergoing. Basically, it analyses sound
        frequencies by a tubular organ containing hairs ranging in size from
        large to small. Each hair resonates to a different frequency, i.e. to a
        different pitch. In mammals this tube is rolled up into a spiral
        known as the cochlea, from its resemblance to a snail. The cochlea
        of mammals contains also the organ of Corti, of which more anon.
        At the same time the ear analyses accelerations by means of three
        semicircular canals. Sensitive hairs detect the motion of fluid within
        them as the body moves and the brain integrates the three sets of
        signals to arrive at the vector. Finally, within a cavity known as the
        lagena, a small lump of stone or mineral concretion rests on
        sensitive hairs and tells the brain which way is up. ... How was this
        complex set of structures evolved?

        To find an answer to that question we must go back to the earliest
        bony fishes. They possessed, as do modern fishes, a structure
        known as the lateral line, running from head to tail on either side.
        At the head end it fans out into a system of canals in the skull. The
        lateral line is a canal enclosing cells armed with sensitive hairs
        embedded in gelatine which detect the motion of the fluid in it and
        which in this way register vibrations in the water or so it is claimed.
        It has also been alleged to register electric currents or to be an
        organ of taste registering chemical changes. But since recent
        experiments have shown that it can distinguish between water
        flowing past it head-to-tail from water flowing tail-to-head, the
        most probable explanation is that it is an accelerometer for straight-
        line swimming.

        Where it came from is totally mysterious, but where it went to is
        the ear. The transformation took place in six or seven stages. As
        evolution proceeded, the canals in the head migrated into the bony
        structure of the head and bent round to form semi-circular canals.
        The ciliated cells were now enclosed in a capsule, still with their
        ends in gelatine. Other parts of the lateral line formed into closed
        sacs: the sacculus, the utriculus and the lagena. In bony fishes, the
        utricle was and is the main detector of posture, for one of these
        sacs became loaded with a mineral concentration or crystal which,
        resting on sensitive hairs, indicated accelerations and decelerations
        and also which way was up.

        When we turn from fishes to terrestrial animals we find the sacculus
        and utriculus have been carried over unchanged, but the lagena has
        wound itself into a spiral. This first occurs in snakes, the process
        being completed in birds and mammals, where the spiral becomes a
        helix: in a word the cochlea aforementioned. In mammals the
        sensitivity of the cochlea is improved by a new structure, the organ
        of Corti, which renders the hairs so sensitive that they can detect
        vibrations whose amplitude is no more than the diameter of a
        hydrogen atom. What was once merely a pressure detector now
        provides for us the miracle of sound.

        So much for the inner ear. The eardrum first appears in the frog,
        lying flush with the skin: snakes have no ear-drum. Then various
        jaw bones are adapted to transmit the vibrations of the eardrum to
        the inner ear. Meanwhile the efficiency of the cochlea is improved
        by the appearance of the basilar membrane.

        Finally the external ear is added to improve directional hearing.

        With all this, of course, went improvements in the brain, most
        notably the power to compare the times at which signals from one
        source reach each ear, thus providing a method of estimating the
        direction in which the source lies.

        Thus, in the course of evolution, there were six major
        developments, two of which occurred in the fishes, two in the
        amphibia and two in mammals. ...

        In contrast with the case of the eye, where undifferentiated cells
        were specialised into the required forms, here existing structures
        have been profoundly modified and even shifted to another position
        in a progressive series of changes which certainly look more like the
        refinement of a plan than the result of a series of happy accidents.

        But the insoluble problem is how and why did a balance organ
        become an organ of hearing? As van Bergeijk pointedly asks: 'What
        prompts the fish to begin developing a sensory apparatus that will
        respond to a stimulus about the very existence of which the fish
        knows nothing?' Van Bergeijk believes that the original balance
        organ would never have evolved mechanisms for hearing but for the
        emergence of the swim bladder. The original purpose of this organ
        is to enable the fish to adjust its density to the density of the
        ambient water and so control the depth at which it swims. Since the
        bladder is sensitive to changes in external pressure, it vibrates in
        harmony with pressure changes in the water. In time these
        vibrations came to excite the ear. Hearing as distinct from the mere
        detection of pressure waves, was born.

        After describing the last part of this process, the adaptation of the
        bones linking the jaw to the skull into a chain of ossicles linking the
        eardrum to the inner ear, Ernst Mayr sweepingly remarks: 'Not all
        the steps in this process are yet entirely apparent, but I think little
        doubt is left as to the principle involved.' If by 'principle' one means
        merely progressive remodelling, the statement is a truism. But if
        'principle' means that chance selection brought about these
        elaborate changes, then there must be very great doubt indeed. Like
        de Beer, Mayr does not seem to appreciate the elementary point
        that demonstrating the occurrence of a sequence of events does not
        explain why they happened.

        But what kind of mutations could bring about the major changes I
        have described? Could cause a tube to roll up into a helix? Could
        cause other tubes to form semi-circular canals accurately set at right
        angles to each other. Could grade sensory hairs according to
        length? Could cause the convenient deposit of a crystal in the one
        place it will register gravity? Even more amazingly, some fishes do
        not trouble to secrete a crystal but incorporate a bit of sand or
        stone. What kind of mutation could achieve this - when and only
        when a natural crystal is not formed? The purpose is fulfilled, the
        means are unimportant. It just doesn't make sense."

        (Taylor G.R., "The Great Evolution Mystery," [1983], Abacus:
        London, 1984, reprint, pp.103-106)

        Taylor, an engineer, for all his willingness to recognise that there was a
        "Great Evolution Mystery", in the end was still a naturalistic evolutionist,
        who could not "make sense" of what his investigations revealed.

        But it *does* "make sense" (to me a creationist who accepts common
        ancestry) if the ear is seen as yet another `construction project' by a far-
        sighted Intelligent Designer!

        CL>The fossils
        >are the evidence, but we are free to interpret them, we can't just say
        >the fossils in themselves are the complete history, if we could only
        >arrange them in just the right order.

        The first objective way to "arrange them in just the right order" is by
        *stratigraphic* (i.e. temporal) "order". Any theory that requires *wholesale*
        ignoring of stratigraphic "order" is IMHO false.

        >SJ>"This regular absence of transitional forms is not confined to mammals, but is
        >>an almost universal phenomenon, as has long been noted by paleontologists. It
        >>is true of almost all orders of all classes of animals, both vertebrate and
        >>invertebrate. A fortiori, it is also true of the classes, themselves, and of
        >>the major animal phyla, and it is apparently also true of analogous categories of
        >>plants. .... In addition to the fact that
        >>they exist, there are other more or less systematic features of these
        >>discontinuities of record that call for attention and require explanation."
        >>(Simpson G.G., "Tempo and Mode in Evolution," [1944]

        CL>The lack of transitional forms is addressed by postulating unknown common
        >ancestors, pushing the timing of divergences further back in time.

        Yes. That is what Darwinists have to do to protect their theory of
        "[c]umulative selection, by slow and gradual degrees". They just "postulate
        a sufficiently large series of sufficiently finely graded intermediates" so they
        are always "able to derive anything from anything else":

        "Cumulative selection, by slow and gradual degrees, is the
        explanation, the only workable explanation that has ever been
        proposed, for the existence of life's complex design. The whole
        book has been dominated by the idea of chance, by the
        astronomically long odds against the spontaneous arising of order,
        complexity and apparent design. We have sought a way of taming
        chance, of drawing its fangs. 'Untamed chance', pure, naked chance,
        means ordered design springing into existence from nothing, in a
        single leap. It would be untamed chance if once there was no eye,
        and then, suddenly, in the twinkling of a generation, an eye
        appeared, fully fashioned, perfect and whole. This is possible, but
        the odds against it will keep us busy writing noughts till the end of
        time. The same applies to the odds against the spontaneous
        existence of any fully fashioned, perfect and whole beings .... To
        'tame' chance means to break down the very improbable into less
        improbable small components arranged in series. No matter how
        improbable it is that an X could have arisen from a Y in a single
        step, it is always possible to conceive of a series of infinitesimally
        graded intermediates between them. However improbable a large-
        scale change may be, smaller changes are less improbable. And
        provided we postulate a sufficiently large series of sufficiently finely
        graded intermediates, we shall be able to derive anything from
        anything else, without invoking astronomical improbabilities."
        (Dawkins R., "The Blind Watchmaker," 1991, pp.317-318)

        But if there really was "ordered design springing into existence from nothing
        [or even something], in a single leap," then Darwinism would be false.

        CL>My model
        >makes this easier to accept, because if skeletal evolution is proceeding only
        >by reduction and distortion of a pre-existing complex of segments, then
        >parallelism is far more feasible than if skeletal evolution were elaborative
        >in the sense of the number of segments.

        I doubt that anyone has a problem with "skeletal evolution ... proceeding ...
        by reduction and distortion of a pre-existing complex of segments". It is
        Cliff's claim that it proceeds "*only*" by that mechanism which remains to be
        demonstrated.

        CL>Where evolution is limited, parallelism
        >is more feasible, than when evolution is utterly open-ended.

        I am not sure what Cliff means here.

        CL>Mammals can be similar to reptiles without having to have diverged from
        >reptiles just at the point where we first see mammals in the fossils.

        The issue is not just "similar". What needs to be explained is "the *perfect*
        morphological correspondence between the [jawbones-earbones]
        conditions in reptiles and in mammals" (see above).

        Cliff's model cannot do that, so he tries to ignore it by hand-waving about
        "common ancestry".

        CL>We can
        >postulate unknown pre-existing mammals, in the trees or wherever; we know
        >the fossils are a sketchy 'record', so why not do this, rather than having to
        >imagine crunching jaw-bones gradually becoming part of the delicate
        >hearing-bone chain?

        It depends on whether one just wants to "imagine" something or whether
        one feels obliged to deal with *all* the *evidence*!

        And the evidence is that "crunching [reptilian] jaw-bones" *did*
        "becom[e] part of the delicate [mammalian] hearing-bone chain" because of
        the "perfect morphological correspondence between the [jawbones-
        earbones] conditions in reptiles and in mammals" (see above).

        CL>Then there are questions about fur, and lactation, and
        >brain size; big things, to be glossed over so readily.

        *I* haven't "glossed over" these!

        [...]

        Steve

        --------------------------------------------------------------------------
        "In mammals a single bone called the dentary (because it bears the teeth)
        makes up either half of the lower jaw. It articulates directly with the
        squamosal area of the skull. Reptiles have a more complex lower jaw with
        no fewer than six bones in either half. One of the bones of the jaw (the
        articular) articulates on the quadrate bone of the skull, a bone not found in
        mammals. All reptiles have a single rod-like bone in the ear (the columella)
        which connects the eardrum to the inner ear. There is no evidence that its
        'simplicity' in any way impairs the hearing of its possessors, who can
        perceive pitch and volume as well as mammals; bird song would be wasted,
        at least on birds, if the columella lacked efficiency and left them partly deaf.
        Mammals possess three bones in the middle ear (stapes, malleus and incus,
        so called because they resemble, respectively, a stirrup, a hammer and an
        anvil); also a complicated inner ear, with the organs of balance and cochlea,
        containing the organ of Corti. ... Consider what such a transformation
        would require. Some early reptile would have scrapped the original hinge
        of its lower jaw and replaced it by a new one attached to another bone.
        Five bones of the lower jaw would have broken away from the biggest
        bone. The jaw-bone to which the hinge was originally attached would, after
        being set free, have forced its way into the middle part of the ear, dragging
        with it three of the lower jaw-bones which with the quadrate and columella,
        formed themselves into a completely new outfit. While all this was
        happening two complicated structures would have developed in the inner
        ear. The organ of Corti, peculiar to mammals and their essential organ of
        hearing, comprises some 3000 arches placed side by side so as to form a
        tunnel. Study the complexity of the cochlea and its nervous connections.
        Add to this the vestibular component of balance, which includes three
        semi-circular canals in planes at right angles to each other. Two different
        kinds of nerve receptor are finely designed to achieve their purpose. Both
        pieces of apparatus are intimately linked by their fluid (endolymph and
        perilymph) systems. There is no evidence that such elaborate evolution
        could, or did, take place. The apparatus is entirely novel; from what
        precursors did it derive?" (Pitman M., "Adam and Evolution," Rider & Co:
        London, 1984, pp.203-205)
        Stephen E. Jones. sejones@.... http://members.iinet.net.au/~sejones
        Moderator: CreationEvolutionDesign@yahoogroups.com
        Group: http://groups.yahoo.com/group/CreationEvolutionDesign
        --------------------------------------------------------------------------
      • Cliff Lundberg
        ... That s not long for we who think in geological time. Thanks for working on something you re not especially interested in. ... The interesting bit is the
        Message 3 of 3 , Oct 9, 2001
        • 0 Attachment
          Stephen E. Jones wrote:
          >I apologise to Cliff for this being two months late!

          That's not long for we who think in geological time. Thanks for working
          on something you're not especially interested in.

          >Who would disagree that there has been "reduction in the number of
          >skeletal parts and loss of symmetry between parts"? I am sure even the
          >ICR would agree with this.

          The interesting bit is the claim that, after the Cambrian Explosion, *all*
          evolution in segmented lineages has been a matter of reduction and
          distortion of parts, that elaboration in the sense of adding new segments
          has not occurred. Of course all evolutionists grant that evolution through
          loss occurs, but they consider it secondary or epiphenomenal, in contrast
          to regular elaborative evolution, which they see as the main theme, even
          though there is no evidence for it other than the Cambrian Explosion itself.

          > The thing to be explained is not "reduction"
          >but how what is later reduced came to be built up in the first place.

          It all needs to be explained, the formation of the highly segmented and
          symmetrical prototype through a sudden multiplication of the body into
          linked chains of identical bodies, and the subsequent limitation to
          reduction in the evolution of gross morphology.

          >It reminds me of Spetner's observation that mutations which lose
          >information cannot be the explanation of the original build-up of that
          >information:
          >
          > "Whoever thinks macroevolution can be made by mutations that
          > lose information is like the merchant who lost a little money on
          > every sale but thought he could make it up on volume." (Spetner
          > L.M., "Not by Chance!: Shattering the Modern Theory of
          > Evolution," Judaica Press: New York, 1997 revised, p.160)

          I don't know what is meant by a mutation 'which loses information.' Mutations
          are changes in information. The quality of genotypic change is not directly
          proportionate to the quantity or quality of any resultant phenotypic
          change. When
          evolution sculpts a complex tetrapod from a symmetrical snake-like skeleton,
          it does so through reduction and distortion; is this a matter of losing
          information?

          As to macroevolution, my model allows elaboration in number of parts only
          via Siamese-twinning-like duplications of virtually the whole body. This
          too can
          be viewed as arising through loss of information. The complete developmental
          program would result in separate organisms; the truncated, damaged program
          does not produce fully differentiated organisms, it produces a group of joined
          organisms. Has information increased or what? I guess I don't care, the
          morphology interests me, not this abstract concept of 'information.'

          >CL>By 'fossil series' I don't mean
          > >arbitrary arrangements of animals based on a general theory of increasing
          > >complexity; I mean fossils showing evolution among indisputably related
          > >animals; the horse series is the classic. (This series shows reduction in
          > >that digits are lost.)

          >Again, I have no problem with the "horse [or any] series" that "shows
          >reduction in ... digits" (or anything for that matter).

          Again, the question is whether you have a problem with post-Cambrian
          evolution being *limited to reduction*; nobody has a problem with reduction
          occurring here and there.

          >I agree with Dawkins in that "what I mainly want a theory ... to ... explain
          >complex, well-designed mechanisms like hearts, hands, eyes and
          >echolocation":

          The heart's mechanism is a simple squeezing, pumping action, the
          evolution of which in some aquatic context hardly seems problematic.
          My model does explain the origin of multi-chambered hearts and other
          paired and lobed organs; these represent consolidations from an original
          state in which every somatic segment had its own such organ.

          Hands are easily traceable to the lungfish limb, that is, hands can
          be formed through reduction of the number of segmented radials
          along this limb.

          As to eyes, the genes show that vertebrates and cephalopods had a
          common ancestor which was morphologically evolved enough to have
          a modern eye. I don't see how theories of vertebrate origins from
          so-called primitive chordates accommodate this datum.

          What's the problem with echolocation? Making a vibration is no big
          trick, nor is perceiving vibration. This seems the sort of thing that
          could be improved gradually.

          >To "explain the sort of complex multidimensional adaptation that ... seems
          >to demand a shaping agent at least as powerful as a deity:

          I believe natural evolution is the shaping agent, but the agent starts with
          a complex, a mass of segments free to be adapted to new uses, or to be
          discarded for the sake of efficiency.

          >Given the competitive nature of science, I would be surprised if there
          >really was an important naturalistic explanation in the past that "has not
          >been refuted, but ... has been abandoned" which some bright, young,
          >ambitious paleontology graduate student did not pick up an run with it.

          The job of paleontology is not to puzzle out history, but to confirm the
          current evolutionary model. No paleontology grad student with instincts
          for academic survival would pursue this issue.

          The pattern of reduction and distortion among skeletal segments
          is not an explanation, but an observation. It cries out for explanation,
          but it's swept under the rug because it doesn't confirm the current
          evolutionary model.

          >CL>In the era of the modern synthesis, scientists
          > >were all expected to support the general theory of gradually increasing
          > >complexity in evolution, and this anomalous generalization offered nothing
          > >in support of that.
          >
          >I would expect that was because "gradually increasing complexity" is the
          >major problem to be explained, when reduction of that "complexity" is not.

          *Why* post-Cambrian evolution is limited to reduction is something that
          needs to be explained. In the sense of *number of parts*, I don't see
          complexity
          increasing gradually, only decreasing. The origin of the complex must be
          explained, but this need not be, and apparently is not, a gradual process.

          >CL>As I have mentioned, Gould grumps a bit about this generalization in
          > >Paleobiology 6:1 (1980): it lacks an explanation, it is not deducible from
          > >probability, consequences cannot be deduced through it.
          >
          >If Cliff will give me the full article reference, including its title and
          >page
          >numbers I will try to get it so I can try to understand what Cliff is driving
          >at. I seem to remember asking Cliff for this before and I apologise if he had
          >already given it to me in the past.

          Title: The promise of paleontology as a nomothetic, evolutionary discipline.
          Pages 96-118. I refer to pp 100-101. But I really only cited this to show that
          Gould does recognize the existence of the principle.

          >CL>Further, the implication is that future descendants will have fewer
          > >skeletal parts and less symmetry among these parts.
          >
          >Not necessarily. If invertebrates had no "skeletal parts" (i.e. bones) and
          >vertebrates were their "future descendants" then the latter had more*
          >"skeletal parts".

          Invertebrates can have hard parts; presumably these were the precursors
          of bones. The number of these parts within an organism is increased
          suddenly via Siamese-twinning, forming vertebrate and arthropod
          progenitors, then decreased slowly via Darwinian evolution, forming
          the varieties within those groups.

          >CL>This is simply extrapolating from a clear pattern; but it is
          > >rather unthinkable for the 20th Century evolutionist, because it
          > >doesn't support the picture of increasing complexity in every
          > >sense; even in this limited sense of number-of-skeletal-parts, there
          > >must be discomfort among Darwinians at this unexpected trend
          > >among segmented organisms such as vertebrates.
          >
          >I doubt that "Darwinians" would find it "unthinkable" or that it would
          >cause them any "discomfort". If they are focused mainly on "the picture of
          >increasing complexity" it is because that is the main problem to be
          >explained. That more complex skeletons can lose "skeletal parts" and hence
          >have "less symmetry" is not a major problem to be explained. Darwin's Origin
          >of Species even contained sections which dealt with the "Use and Disuse of
          >Parts".

          The problem is the confusion between 'complexity' and 'number of parts'.
          Darwinians assume that increase in number of parts occurs, while the
          evidence shows that only decrease occurs, subsequent to the CE, while
          of course marvelous adaptations are gradually evolved as parts are
          lost and distorted.

          >CL>There are many supposed evolutionary transformations that do not
          > >fit this pattern at all, such as the evolution of land vertebrates from
          > >Coelacanths
          >
          >What makes Cliff think that "land vertebrates" arose "from Coelacanths"?
          >AFAIK no leading evolutionist makes that claim.

          Well, they used to. They're getting more careful, saying less and less.
          I believe the general view is still along these lines, certainly presuming
          some elaboration in the number of limb bones.

          >CL>or snakes from reptiles with fewer segments.
          >
          >Indeed! Why does Cliff call "snakes from reptiles" a "supposed evolutionary
          >transformation"? Is he claiming that "snakes" did not arise "from reptiles
          >with fewer segments"? If so, what is his *evidence*?

          My model doesn't admit elaborations in number of segments. I have to
          presume that unknown many-segmented early snakes existed. There is no
          fossil series I know of illustrating the gradual elaboration of a snake
          skeleton
          over time. Snakes are not good candidates for fossilization, being able to
          escape the mud which can mire and entomb both fishes and tetrapods.

          If I am making the negative claim, that snakes did not evolve from reptiles
          with fewer axial segments, and you are making the positive claim, that
          they did so evolve, why should I be the one required to present evidence?
          My opinion is based on an observed pattern, yours on blind faith in
          traditional Darwinian phylogeny.

          >CL>And the ultimate end, with segments down to a bare minimum, and no
          > >parts free to be adapted to new functions, is really unthinkable.
          >
          >This sounds to me like Cliff is trying to `hype' his theory. I doubt that
          >anyone has a problem thinking of "segments down to a bare minimum, and
          >no parts free to be adapted to new functions".

          The unthinkable part is that a lineage would be stuck in such a dead end.
          Darwinian/Dawkinsian evolution is supposed to open-ended and unlimited.

          >CL>But the facts are there, we have to recognize the trend.
          >
          >What there could be disagrement about is Cliff's claim that it is necessarily
          >"the ultimate end" and a "trend". What is "a bare minimum" anyway?

          Ultimately, there is no end. There could always be more Siamese-twinning,
          for one thing. "Cliff's claim" happens to be an observable, long-established
          general truth. You don't know about it because it was purposefully omitted
          from the Darwinian canon you were taught all your life. I don't know what a
          bare minimum has to be, but I do believe that a simple unsegmented organism
          dropped into a lot of new environments will be at an evolutionary disadvantage
          in competition with an organism consisting of many skeletal parts, parts which
          are free to be adapted to new uses.

          >What is Cliff's model's testable prediction? That there is a "trend" in *all*
          >lines of organisms towards an "ultimate end" of *one* of every part?

          Yes, that is the observed pattern, reduction and specialization of parts.
          (I should point out that I use 'part', 'bone', 'segment', 'homolog' etc fairly
          interchangeably.) Testable predictions? Well, that the pattern will hold,
          is one. Another would be the prediction that evidence of the supposed
          progenitors would be found, if it were looked for. Current practice is to
          look for the opposite, 'primitive chordates', and interpretation is a big
          factor
          in early fossils. Another prediction might be that such an evolutionary model
          would prove successful in computer simulations, in competition with alternative
          models which involved elaboration in number of parts.

          >If so, what is the evidence of this? Some many-segmented organisms like the
          >centipedes and millipedes, and snakes for that matter, have remained the same
          >for hundreds of millions of years and show no sign of reducing their number of
          >segnents.

          Stasis is no problem. But where is the evidence showing elaboration in number
          of segments in any lineage?

          >CL>Deduction from probablility is easy, once the pattern is understood
          > >and accepted. Random mutation, acting upon an array of symmetrical
          > >elements, should produce loss of elements and distortion among
          > >formerly symmetrical elements.
          >
          >Agreed, but only if the "elements" have no selective value. But then so what?

          Elements that have no selective value are selected out as new morphology is
          sculpted.

          >CL>Adding new segments, complete
          > >with infrastructure and functional enough to be advantageous, and
          > >symmetrical with existing segments, seems a much more difficult
          > >thing for random mutation to accomplish.
          >
          >Agreed. In those cases, maybe it was not by *random* mutation? That is,
          >it was supernaturally directed?

          That is your department. But I am interested in knowing what points in
          the course of evolution you consider intractable for evolutionary theory
          and therefore possibly interventions.

          >CL>A formative process must be postulated, during which a duplicative
          > >process like Siamese-twinning formed many-segmented colonial
          > >organisms, which subsequently consolidated into the integrated
          > >organisms which form the varieties of segmented organisms.
          >
          >Has Cliff any actual *evidence* for this "Siamese-twinning" among
          >"colonial organisms"?

          No, this must be deduced from the evidence, it is not directly observable.
          Of course we have the example of existing colonial organisms.

          >Or that "Siamese-twinning" is heritable? i.e. if a male set of Siamese
          >twins mates with a female set of Siamese twins that their offspring
          >will be a set of siamese twins?

          Why not? It would seem obvious that such parents might be more
          likely than average to produce Siamese-twin offspring.

          >Siamese-twinning is a post-conception developmental disorder, so how
          >could it be inherited?

          All morphological novelties are 'post-conception developmental disorders.'
          If such disorders ultimately stem from genotypic factors, they are heritable.

          >Which "colonial organisms" were these exactly anyway?

          Nothing like the known colonial organisms, these are theoretical.

          CL>Why couldn't such a duplicative process add segments within a
          > >segmented organism? Well, in biology anything *could* happen, but
          > >we deal with what is probable.
          >
          >Even Dawkins accepts that there have been "segments [added] within a
          >segmented organism":
          >
          > "Stretched DC8 macromutations are mutations that, although they
          > may be large in the magnitude of their effects, they turn out not to
          > be large in terms of their complexity. The Stretched DC8 is an
          > airliner that was made by modifying an earlier airliner, the DC8. It
          > is like a DC8, but with an elongated fuselage. It was an
          > improvement at least from one point of view, in that it could carry
          > more passengers than the original DC8. The stretching is a large
          > increase in length, and in that sense is analogous to a
          > macromutation. More interestingly, the increase in length is, at
          > first
          > sight, a complex one. To elongate the fuselage of an airliner, it is
          > not enough just to insert an extra length of cabin tube. You also
          > have to elongate countless ducts, cables, air tubes and electric
          > wires. You have to put in lots more seats, ashtrays, reading lights,
          > 12-channel music selectors and fresh-air nozzles. At first sight
          > there
          > seems to be much more complexity in a Stretched DC8 than there is
          > in an ordinary DC8, but is there really? The answer is no, at
          > least to
          > the extent that the 'new' things in the stretched plane are just
          > 'more
          > of the same'. (Dawkins R., "The Blind Watchmaker," 1991, pp.234-235)

          *Even* Dawkins? But Dawkins is the archetypical orthodox Darwinian. His
          airplane analogy speaks of inserting something into the middle of the axial
          skeleton, something that *never happens* in morphological evolution. For
          him, evolution can do anything, anywhere, anytime, the evidence be damned.

          Of course his point about the difficulty of simply increasing the size of
          a complex organism is valid. But that is why Siamese-twinning works as
          a means of increasing size suddenly; the newly formed organism is
          much larger, but this is no problem for the viability of the members of
          the aggregation, as their scale is unchanged. Adaptation to the new overall
          size and condition can be gradual, while individual segments gradually lose
          their physiological independence.

          >CL>Duplication of the whole body is a feasible and observable phenomenon;
          >
          >It occurs within humans, i.e. identical twins. But does it happen in other
          >taxa? If so, which ones?

          I should look into this sometime. As a naturalist, it never occurred to me
          that man would be unique in this respect. I know fish embryos are sometimes
          not fully differentiated; these are just regarded as deformed, their lack of
          viability in the real world is so patent. But I suppose they might be kept
          alive.

          >CL>but having one Siamese-twin
          > >be so partially formed that it amounted to but one skeletal segment,
          > >perfectly positioned, is unlikely.
          >
          >Why does Cliff think it needs a "Siamese-twin" to duplicate a "skeletal
          >segment"? Duplication of Hox genes are claimed to be able to do it:

          > "But there is another crucial aspect in which at least fruit flies,
          > frogs, zebra fish, chickens, mice, and humans are similar. Their
          > bodies are segmented. In fruit flies, as in other insects, as
          > well as in
          > crustaceans such as shrimp and lobsters, the musculature and the
          > outer hardened shell also differentiate into series of segmented
          > units
          > that resemble the overlapping plates of a suit of armor. In
          > vertebrates, the muscles of the trunk and even of the limbs arise as
          > segmental units, as do the bones that lie internal to them. The
          > development of segmentation in such a diverse array of animals did
          > not arise purely by chance in each animal or in the immediate
          > ancestor of each animal. One of the biggest ongoing discoveries in
          > developmental genetics is that all segmented animals studied to date
          > share similar regulatory molecules, which orchestrate the
          > development of segmentation. When these molecules were first
          > discovered, they were called homeobox genes and referred to as
          > Hox genes for short. The abbreviation Hox is still used to designate
          > the regulatory genes that are involved in the development of
          > segmentation and segmented structures, but the term homeobox
          > gene now covers the entire gamut of regulatory genes that are
          > fundamental to an organism's development." (Schwartz J.H.,
          > "Sudden Origins: Fossils, Genes, and the Emergence of Species,"
          > John Wiley & Sons: New York NY, 1999, p.35).
          >
          >Interestingly, according to Google, Cliff's "Segmentation and Vertebrate
          >Origins" web pages at http://www.cab.com/segment/tablecon.html don't
          >seem to contain the words "hox" or "homeobox". If this is in fact the case,
          >then it sounds like Cliff is ignoring modern developmental genetic
          >explanations in order to push his "Siamese-twinning" explanation?

          My theory is morphological, not genetic. If there are genetic arguments
          against my model, I'm interested. But I'm not throwing in possible tie-ins
          just to sound up-to-date. Hox genes have to do with the basic blueprints
          of gross morphology, and show that the common ancestors of all organisms
          with these genes already had a body plan involving a segmented axis and
          limbs. This doesn't seem incompatible with postulating an archetypical
          structure. Archetypical gene, archetypical structure. No problem. That's all
          I can say about hox genes.

          >CL>The Cambrian Explosion does not mark the advent of DNA, or cells,
          > >or hard parts. It is an explosion of experimentation at the level of
          > >gross skeletal morphology, and the formation of segmentation is
          > >the gimmick that sets it off.
          >
          >These were mostly invertebrates, with one or two boneless notachord early
          >vertebrates (e.g. Pikaia), so it can hardly be said to be an "explosion
          >... at
          >the level of gross *skeletal* morphology" (my emphasis).

          We tend to neglect the inverts. My model is concerned with segmented
          organisms, particularly vertebrates. Various major phyla appeared in the CE.
          No new phyla have emerged since. I don't accept your implication that such
          as Pikaia or Amphioxus are early vertebrates; this would be inconsistent
          with the pattern of reduction and distortion shown by the fossil evidence.
          Of course Pikaia is early, and some may call it a vertebrate; I mean it
          can't be the progenitor of vertebrates with more skeletal parts, more
          segments.

          > >SJ>What Cliff seems to want me to be is personally *credulous*, so that I
          > >>just accept his vague model on *his* say-so, and wave away any
          > >>inconvenient facts (like the almost perfect morphological and temporal
          > >>correspondence between reptilian and mammalian jaw-ear bones), with
          > >>vague answers like it being the result of "common ancestry" with some
          > >>unknown "progenitor" ~300 million years earlier!

          This correspondence is not inconvenient. It is the result of parallel
          evolution. This would be most unlikely if evolution were elaborative
          in number of parts, as newly evolving parts would have to take the
          same shape they were taking in another distinct lineage. But where
          evolution is limited to reduction of an existing complex of parts,
          parallelism is more feasible, as the options are limited, and the parts
          in question are already there, not newly evolving. Where parallelism
          is more feasible, common ancestors can be set further back in time;
          there is no need to presume recent common ancestry to explain detailed
          similarities.

          >CL>At www.cab.com/segment/progenit.html I describe the model in detail,
          > >depicting the formation of segmented progenitors in clear pictures. I don't
          > >see how this can be called a vague model.
          >
          >What is "vague" about Cliff's "model" is that it has no connection with
          >reality, i.e. with the *name* of any *actual* organism as revealed in the
          >*fossil record*. There is no *name* of any organism in the above web page.
          >There are no footnotes in it referencing the scientific literature.

          I don't see how new ideas could ever be introduced under these criteria.
          I should give my progenitor a name, that might help. But I don't think a
          fossil
          is going to be found. Its existence in geological time would have been too
          brief.

          >Cliff's model seems to be just that-a model-which Cliff has made up off the
          >top of his head? I admire Cliff's ability to do it-it probably takes powers
          >of imagination of a high order.
          >
          >But just imagining theoretical "progenitors", while it is no doubt an
          >enjoyable pastime, does not mean that it has any relevance to *what
          >actually happened*. To do that, Cliff has to tie his model in with the
          >fossil record.

          The tie-in is the explanation of the great pattern of reduction and distortion,
          which is sorely lacking in current theory.

          >CL>The correspondence among reptilian and mammalian skull bones is
          > >obvious, and it proves common ancestry.
          >
          >That two different organisms have a "skull" *at all*, "`proves' common
          >ancestry"! But the question is: how *close* was that "correspondence among
          >reptilian and mammalian skull bones" and hence how *close* was that "common
          >ancestry"?
          >
          >If Cliff's theory cannot explain "the perfect morphological correspondence
          >between the [jawbones-earbones] conditions in reptiles and in mammals":
          >
          > "The important point to notice in these changes is the perfect
          > morphological correspondence between the conditions in reptiles
          > and in mammals. All the elements that are cartilage-bones in the
          > former are so also in the latter: the same is true of the membrane-
          > bones and their relative positions correspond exactly. This
          > correspondence also extends to minute details. The columella in
          > reptiles is frequently pierced by a hole through which the stapedial
          > artery passes; this is constant for the stapes of mammals, and is
          > the
          > reason why it is called the 'stirrup'. The lateral head vein runs
          > back
          > medially to the quadrate in reptiles and to the incus in mammals.
          > The facial nerve passes out of the brain case and runs backwards on
          > the median side of the quadrate in reptiles and of the incus in
          > mammals. The nerve passes above the tympanic cavity on the outer
          > side of the stapedial artery and gives off a branch, the chorda
          > tympany which runs forwards above the tympanic cavity and then
          > down on the median side of the lower jaw elements, articular or
          > malleus, in exactly the same way in reptiles and in mammals."
          > (deBeer G., "Homology: an unsolved problem," [1971], in Ridley
          > M., ed., "Evolution," Oxford Readers, Oxford University Press:
          > Oxford UK, 1997, p.217)
          >
          >then at best it is not a general theory and at worst it is a false theory.

          You and the Darwinists would have titled de Beer's book Homology:
          a *solved* problem! You take it as simply descriptive of the Darwinian
          facts. But all these accurate details are being pressed into service to
          support a larger view which is inaccurate. These similarities can be
          attributed to parallel evolution, so the evolution of one group from
          another does not need to be presumed.

          >CL>I prefer to think one did not
          > >evolve from the other, because of the unlikelihood of the more complex
          > >mammalian hearing bones being elaborated from the reptilian format,
          > >and because my general model tends to make me accept that there
          > >were important unknown progenitors at various levels.
          >
          >Cliff has hit the nail on the head! That "mammalian hearing bones" arose
          >from "the reptilian format" does not explain *why* it happened:
          >
          > "Embryology and paleontology provide adequate documentation of
          > the `how,' but we would also like more insight into the `why.' In
          > particular, why should such a transition occur-especially since the
          > single-boned stapedial ear seems to function quite adequately (and,
          > at least in some birds, every bit as well as the three-boned
          > mammalian ear)?" (Gould S.J., "An Earful of Jaw", "Eight Little
          > Piggies: Reflections in Natural History," Jonathan Cape: London,
          > 1993, p.106)

          I'm not going to explain why the mammalian ear structure evolved from
          the reptilian when I don't believe mammals evolved from reptiles.

          >CL>The fossils
          > >are the evidence, but we are free to interpret them, we can't just say
          > >the fossils in themselves are the complete history, if we could only
          > >arrange them in just the right order.
          >
          >The first objective way to "arrange them in just the right order" is by
          >*stratigraphic* (i.e. temporal) "order". Any theory that requires *wholesale*
          >ignoring of stratigraphic "order" is IMHO false.

          We can't assume that stratigraphic priority proves ancestry. AFAIK
          modern cladistics ignores stratigraphy.

          >CL>The lack of transitional forms is addressed by postulating unknown common
          > >ancestors, pushing the timing of divergences further back in time.
          >
          >Yes. That is what Darwinists have to do to protect their theory of
          >"[c]umulative selection, by slow and gradual degrees". They just "postulate
          >a sufficiently large series of sufficiently finely graded intermediates"
          >so they
          >are always "able to derive anything from anything else":

          Postulating unknown common ancestors is an alternative to postulating
          missing links. Postulating common ancestors means not having to
          postulate intermediate forms to explain similarities.

          >CL>My model
          > >makes this easier to accept, because if skeletal evolution is proceeding
          > only
          > >by reduction and distortion of a pre-existing complex of segments, then
          > >parallelism is far more feasible than if skeletal evolution were elaborative
          > >in the sense of the number of segments.
          >
          >I doubt that anyone has a problem with "skeletal evolution ... proceeding ...
          >by reduction and distortion of a pre-existing complex of segments". It is
          >Cliff's claim that it proceeds "*only*" by that mechanism which remains to be
          >demonstrated.

          This is why the pattern of reduction and distortion among segments is
          interesting. It seems there is no direct evidence of gradual evolutionary
          elaboration in the sense of number of parts, while there is plenty of
          evidence of the opposite trend. There is room for theories that take
          the evidence at face value.

          >CL>Where evolution is limited, parallelism
          > >is more feasible, than when evolution is utterly open-ended.
          >
          >I am not sure what Cliff means here.

          Where evolution is constrained to follow certain channels, diverging
          lineages may follow the same paths. If evolution is utterly open-ended
          and unconstrained, following the same paths is unlikely.

          CL>Mammals can be similar to reptiles without having to have diverged from
          > >reptiles just at the point where we first see mammals in the fossils.
          >
          >The issue is not just "similar". What needs to be explained is "the *perfect*
          >morphological correspondence between the [jawbones-earbones]
          >conditions in reptiles and in mammals" (see above).

          Common ancestry explains it. Evolution of one from another is not
          logically necessary.

          >Cliff's model cannot do that, so he tries to ignore it by hand-waving about
          >"common ancestry".

          While you hand-wave about jaw-bones transforming into ear-bones
          for no reason, while scales become fur, and lactation comes out of
          nowhere.

          >It depends on whether one just wants to "imagine" something or whether
          >one feels obliged to deal with *all* the *evidence*!

          Dealing with a general pattern, that of reduction and distortion of
          segments, is dealing with all the evidence.

          >And the evidence is that "crunching [reptilian] jaw-bones" *did*
          >"becom[e] part of the delicate [mammalian] hearing-bone chain" because of
          >the "perfect morphological correspondence between the [jawbones-
          >earbones] conditions in reptiles and in mammals" (see above).

          The morphological correspondence is obvious. What is not obvious is
          why one would make the difficult claim of direct ancestry rather than the
          more modest but less speculative claim of common ancestry, as an
          explanation of the correspondence. I suspect the main motivations are
          sympathy for the old chain-of-being arrangement, simplistic stratigraphic
          interpretation, and a Darwinian belief in the ability of anything to 'morph'
          into anything else over time. A better way is to take the observed pattern
          of evolution seriously, to recognize the fragmentary nature of the fossil
          evidence, and to postulate unknown common ancestors rather than
          unknown transitional forms.

          Cliff
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