Are human tails an example of macroevolution?

I do not see how Faith’s description of human tails as a ”rope’ can be distinguished from from Eramus Darwin’s notion of “a filament” as cited by GS Carter: If these words in English are comparable (rope-filament)then what you are asking could be asked about ANY part of anantomy that is deemed important in the process of species change. Since these bones do not posses any large lateral projections I do not see how one is going to even think beyond E. Darwin's "revolution."I take it then you are explicitly asking how creationists "revolve" this "monster" in their minds. I would bet you, and I will go out on the internet and search, that modern creationists have some response to the issue of degeneration. If not I would not hold my breath that they will not have one.

Thanks for reply Bernd.I will respond to the first paragraph and then go back to the firs post and answer your second paragraph in message 10. Thanks again for asking!!I do not think it is difficult to "read" the Grandfather's use of the word "filament" as a precursor idea to Charles' use of "common descent"? Yes???Assuming we get that far, I should note that Darwin derided comparisons of his work to Lamarck's when compared to his Grandfather ( I will show this quote Gould quoted if it is critical, I doubt this is either).Now look CLOSELY at how Erasmus thought out the transformation and notice how the Elder Darwin leads his "mind" to the notion of a "filament" as a conclusion and unity of the thought of biological form-making and translation in space. As an aside about his grandson to be writing, it is quite obvious that unlike Lamarck Eramus presents a style of argument that Charles simply made extended and overwhelming but I will leave that as my own opinion for now lest it might confuse you if you are still with me on this interpretation.Issac Newton's book on Opticks had been around for almost a century by the time E.Darwin wrote and in the end parts of that work one can think Newton "revolving" 'metamorphisis' in his mind purley interms of the relation of bodies and light (and heat). So assuming that my earlier reference to "revolution" is not suspect I think we can easily enter the E.Darwin quote at the point that most closely resembles a current issue - that due to the difference of artifical and natural selection aka domestic breeding without having reached the "third" rotary 'gear' in Grandads thought process which becomes the principle one in the "sons'". But now notice that some of the words that the Grandfather uses ARE NOT purely "evolutionary" as we read them today but contain linguistic usages that really belie a non-evolutionary perspective (let's even leave aside the phrase "led to believe" etc). He speaks of a "PLAN" but he does this AFTER he mentions 'men' and ONLY with respect to WARM-BLOODED creatures, what about snakes? (I have my own ideas). So by the time the speculatively thinking Erasmus reaches his conclusion he has actually thought through some anthropology rather than strict evoluionary psychology say thus the term "filament" IS NOT stricly referring to common descent without the modifications and future mutations of Darwinism and post-Darwinian biology.In the context of E.Darwin's restricted reference to taxonomy I see no reason that the circular symmetry and labileness of a rope or a filament IS ALL that is being cognized here, whether the tail of human through it common ancestry or the notion of the Flesh Faith referred to. Without a discussion of clade geometry which is not found in E.Darwin and single leveled by C.Darwin except in diversification despite the appearence in the words beling form-making it really only expresses translation in space (hence the puncutations etc.).

You asked me

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Besides that, please reread my opening post, where I indeed have asked how creationists “revolve” this “monster” in their minds, given that they probably can’t acknowledge “the recurrence of a formerly expressed allele” nor the origin of a complex structure by mutation.

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Notice that it is "YOU" not an iconic "creationist" that revolves the mutilation or monster mentally.

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For creationists the human tail is the result of a mutation and not “the recurrence of a formerly expressed allele” - as Faith put it - because that would be evidence for a shared ancestor of humans and great apes.

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This has interesting consequences for the creationist viewpoint.

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For one this implies that benefical mutations should be quite common.

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Well it did not take long to find out a creationist position on the internet.I typed “human tail creationism” into Google and the first entry returned was:
Evolution and the Human Tail (#117)
by Duane Gish, Ph.D.
which reads a transition between an evolutionary and a creationary view precisely as I surmised (about lack of lateral projections) where Gish had

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First of all, the caudal appendage does not contain even rudimentary vertebral structures

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Gish’s argumentation rotates between two sentences:

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How can it be said that the presence of this "tail" brings us tangibly and inescapably to the reality of evolution if we cannot exclude the possibility that it is nothing more than a dermal appendage coincidently located in the caudal region? As a matter of fact, even a superficial reading of Ledley's article makes clear that this so-called tail was no tail at all but was nothing more than an anomalous growth coincidentally located in the caudal region.

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which seem to NOT deviate from my reading of E.Darwin in GOING from the first sentence into the second and the second can be accomadated if I was writing as a creationist apologist at the issue of “laws of growth” that Darwin subsequently admitted but Gould deprecated. It would only remain to argue against Gould. This I do repeatedly here on EVC.Yes it is frustrating to me when I can not be understood on EVC but this is not really my fault it is the real difficulty of a proper cut among creationists and evolutionists that is in error.It is one thing to say that a creationist can not admit recurrent allele expression and another to state it exists for a particular trait or anatomy.Desptie the fact that you presented a rather bonier example than Gish, Gish nonetheless said, “If malformations may possibly be due to the expression of genes inherited from distant ancestors but long suppressed” it is hard to see how you are generalizing to all creationists except when you make it A FUTHER condition in the revolution that mutation of a complex trait must be thought in the rotation.So we have two questions rather than an answer.
Do you have evidence that your depiction is falsely explained by Gish’s

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If this caudal appendage were due to a mutation, the mutant gene would be passed on to offspring and would eventually be reexpressed in some of those offspring. This has never been known to occur. The anomaly is thus not due to a mutation but to some disarrangement that occurred during embryological development.

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????????????????And is there evidence that the "occupation" of a human tail IS the result of a complex mutational existence rather than a narrowed or broadend developmental constraint?Lamarck spoke of "motion" and Cuvier divided anatomy by locomotion. It is hard for me to see how a creationist with a moveable tail beyond what Gish commented on, must MEAN that there was a prior generational benefit necessarily. Unless of course the rotation is done wholly by YOU as a creationist. In that case I would not have thought you would have said,

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For creationists...

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Correct me if I am wrong. Where was the "implication" here??? I assume that you are not going to say that where Gish means descendant you mean offspring. If so the difference splits hairs and can not function across the space E.Darwin provided his grandson to artifically devolve or preselect as per the form made.

Thanks for the honesty Equinox.I did not even have any idea that you even tried to read my posts. I do not think we have ever had any exchange of comments on EVC.As for me using a simple link to creationist literature this time, well, that is all that was called for.But look, I can get very very clear and clean if and when the argument that I making hay in gets to that place. Because it is rare for someone to make it to a third repeition with me is part of the reason the issue stays as I have said once before, "muddy."In this case did you see how Bernd's question actually gives rise to TWO MORE biologically?If not let's get really clear and clean,Is there any evidence that human tail morphology has a functional purpose for the human lineage? THAT is what is at issue.Look at a snake and notice that some pythons have "legs" or spurs rather. Does this mean by this anatomy that a snakes legs are just anomalous growths or do they have some function that might be selected for and result in populationally variant allele fluctuations for its existence? Well, snakes DO use thier "spurs" during courtship, so it is possible that their legs are not like a human tail as Gish suspected as being caused by deviant embryogeny but instead are mutations that who knows, might cause snakes to HAVE longer legs in the future.I, personally, do not have any evidence about human tails, but given Gish's response I would doubt there is any indication that human tails result in differential human reproductive success (prevention of anal sex etc.).If Bernd wants to draw the conclusion that tails are a problem for creationsists BECAUSE admitting a functional use entails common anscetry with MONKEYS (which unlike apes really DO use their tails a lot) then he has to first show that human offspring with some freqency selectively and activley exhibit such and so survive elseI see NO WAY to deny Gish his response , ESPECIALLY given the current evo atmosphere of developmental constrainsts and evo-devo. This is not the same issue necessarily as of human vs chimp DNA.When I asked Bernd for the implication, I was asking HIM for what IN ANY PROCESS OF THOUGHT OF EVOLUTIOANARY THEORY enabled him to infer that there was a benefical mutation IN THE ^HUMAN^ TAIL. There is clearly a benefit for monkeys but where is the beneficiary extant among Homo sapiens? I would suspect like being diagnosed, having a tail is likely a social detriment rather than a benefit.There is no bad blood between you and me so you do not need to apologize to others. As for me, well, in this case I may need to give you personally some more informaton about ideas of "constraint" so that there is no "slogging." Just try to respond to this ONE POST. I'll do my best to clean it up and make it even clearer if that is needed.Edited by Brad McFall, : ? markEdited by Brad McFall, : small wordsEdited by Brad McFall, : word "to"

I will answer

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When on the other hand there is an existing pathway to develop a tail in humans which merely is repressed, how is this not evidence for a distant ancestor with a tail?

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very directly by attaching a response to your other post to me after I read your link(s). It may take me through weekend because I want to clear up some readings I have been making of Gould, a little farther. I will not skip the question immediately above in this thread but WK already said what was necessary(heritbility vs nonheritability)(A developmental constrait causing phenotypic expression clinematically is deviant and not necessarily heritable (in general)). I will show how a latent genetic affect can effect non-heritable expression (neophenogenesis is a case study) in general, but I will also look for some evidence that human tail expression may not be developmental deviation from Waddington's canalization as understndable in post-neoDarwinism.And if this is stuff you already understand... the existence of a "tail" for a human or a "leg" for a snake may imply non-existence of such a phenetic in an ancestor of such a grade if the PLAN or Bauplan implies THROUGH THE CONSTRAINT certain boundary conditions on form-making that sequester placement in "morphospace" proactively (having to do with whether the Waddington canalization is widened or narrowed). My sense of these spatial relations is not as good for mammals as it is for reptiles and amphibians where deviation from the central midline is easier to "interpret."You seem to be starting from the thought that creationists have the idea FIRST that the tail is a vestigial organ for humans. I have tried to present a different path of possible creationist thought.When I first started posting on the ICR web forum, before I was posting here, I noticed there was a tendency to speak about "vestigiality" a bit much. If ICR still has its discussion forum cached it might be possible to see how I dealt with this issue post by post, but I have not seen the Forum since then (about 1998).If your issue REALLY has to start with a "vestigial organ" then the ANSWER has to do with the notion of "WILD TYPE." Is this the direction you are going (or wait till I post a second time to see an alternative).Edited by Brad McFall, : spelling

I will try to slug through but it is going to be a very short trip for really a much longer needing replies.The short is that when thinking about snakes one ends up with a thought about oxygen in fish BEFORE one considers the issues of warmbloodedness and ape vs monkey behavior when beyond birds and or dinosaurs. At least that is how it works for me. Thus BEFORE I think about whales by any analogy I have to deal with gills in salamander larvae. Some day I will give the warmbloods more than a ramet of a chance. Sorry that IS my peculiar BSM response. This is what Equinox thought might have something in it. It does. I will strech THAT out further.When thinking about snakes and legs one is actually trying to think about classification of SQUAMATES (lizards and snakes (and I dont suspect you will say that lizards do not have legs in the same sense you ask if humans have tails or not))at least. The point I was making was in trying to distinguish "complex genetic mutation" hence 'legs' IF LEGS were selected and inherited in a past (commonality of lizards and snakes)(thus the evolutionist who thinks from fins to legs to warmbloodedness is likely to START here) from developmental deviation or side-consequence of some other acquired (not necessarily Lamarckian)character LATERALIZATION of SWIMMING MOTION (issue of how man digits fossil fish had). Thus human might have tails and have not legs as weird as it sounds. I have doubted this is the case and am trying to see where the evidence is that a human "tail" is something other than a NON-bilaterally symmetric trait. If all the evidence of tail morphology in humans is radially symmetic or nearly so to any concept of possible adaptiveness I will be justified in holding that the tail man IS UNLIKE (grammatically)the leg of squamate (even though there is osteological phenetic similarities). The existence of BONE without ennervation seems to speak in favor of my current opinion IN THIS THREAD or filament.If the bone has processes that can likened to monkey functional tails I will alter my suspicion but till then... the LEGS of snakes or whales HAVE TWO SIDES, on the left and on the right. Again, I have not thought much about whales so back to snakes.The spur you might think or say has just as little morphological variety as a human tail as we have seen presented on EVC but did you also know that in addition to a forked tongue the snake has HEMIpenii
SPLIT down the middle and the male snake will ALTERNATE which side it copulates on? This induces a Behavorial component to the mophology that I have doubted is in existence for the human dermal growth s0-called by Gish. It may be that the correct scope of anantomy needed to a proper discussion of the snake LEG involves also the PENIS. I do not know. But THAT opens up a whole large area when one starts to uncover the reproductive behavior of both males and female squamates. I do not know that the spur is an "anchoring" mechanism. Have you seen this so described or is that your idea??It could be that the spur is used to change the position of the female so that the male can alter which side "HE" is moving into. I just have not read enough of this literature to know. As far as if the structure itself is only for use "in sex" and nothing but "circumstantial evidence" you should understand that much of the differences in the higher level classification of lizards and snakes relies on the relation of the vertebra via the muscles to the skin but with the existence of spurs this changes THAT homogneous perspective definatively thus it seems to indicate relation OUTSIDE the lizards and snakes rather than sexually inside it (unless one was to relate clades to sex dimorphism (I have not seen such a paper)).

This is not my second reply. Just a quick clarification please.Did you mean"apoptosis" when you wrote

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apostasis

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or was the lettered ("apo")prefix what was intended with ? If the latter did you have some meaning of stasis that you might reliquish please? Pretty please with sugar on top?? Can you refer to some paper or discussion of regulatory genes that feed forward the "apostatic" state?Edited by Brad McFall, : sentence tenseEdited by Brad McFall, : "?"

It was not as simple as just sitting down and deciding what I think especially because you raised the particular notion of APOPTOSIS and I assume even though you did not mention it that when you wrote “regularity” gene you also had meant regulatory gene.
Yes indeed
EvC Forum: All about Brad McFall.
Modulous is correct there are strong similarities between my own ideas and Gould’s.I am having to read Gould’s 6 or 7 pages below

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as to ACTUALLY what I think about Gould’s distinction about rates vs direction in evolutionary change in the footnote on page 1030. As the Pastor at my Church
No webpage found at provided URL: http://www.firstpresithaca.org/10_01_06.htm
is in his second week, past, lecturing/sermonizing on Job and has gotten to the THREE critics of Job today I can “observe” that where Gould wanted to get to “urge”, “compel”, or “make” in the BIBLICAL footnote on page 1026 he might have better thought “pray.”It is nice that you are asking the question in terms of post-modern science rather than 60s conceptuality so please bear with me while I make some permanent mental decisions about this chapter of Goulds’. I have thought my way through the chapter a couple of times already but I have not put out my ideas in black and white, (rather in colored sand) which is what is required by my contrary Nursery Ryhme that you have called for an answer from. The garden grows nontheless.As a hands down, heads up I am also looking strictly at the following texts.

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Edited by Brad McFall, : wrong ref label on picEdited by Brad McFall, : removed "is"

Ok, then I will have to DEFER to I.Newton where he "figures" the formation we have in the letter "X" between the eyes and the brain (anatomically or metamorphically but not cladistically)where you note E.Darwin denoted "filament."I will refer back to your excellent communication via E.Darwin in a later reply and back to my own attempt at

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Without a discussion of clade geometry which is not found in E.Darwin and single leveled by C.Darwin except in diversification despite the appearence in the words beling form-making it really only expresses translation in space (hence the puncutations etc.).

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with a rewrite. Part of the delay in my response is that depending on how one squares out with Gould on rate vs direction there is an implication for me (maybe not you? I dont know yet)as to a narrowing or widening of the canalization concept (which I left open for purpose of communication in this thread)I am working on reading through POSITIVE notions of constraint.Sorry for the word "beling" I had meant the word "belie", "indicate" or "give rise to."
http://www.m-w.com/cgi-bin/dictionary?book=Dictionary&va=...
(belying)Also you might be able to confirm if I am correct that it was GGaylordSimpson who first worked out the notion of throw-back or atavism BUT IN MAMMALS only?? That is what I recall.Edited by Brad McFall, : atavism-throwback

It appears that there are clinical attempts to morphologically differentiate two kinds of human "tails". This is what Bernd was pointing out with his first picture. shortened linkThe Gish article that I linked to stresses the "pseudo"tail end from the descriptions.We had pictures of a human tail on EVC before that I and perhaps NJ might have been refering to.
EvC Forum: Smoking-Gun Evidence of Man-Monkey Kindred: Episode II... TailsThe issue physiologically as Bernd has been linking to has to do with neuralation and the relation of cell death along an axis or causal with neurualation but this does not necessarily speak sufficiently for the apparent distinction of Great Apes without tails (for me when the issue comes to heritibility) with/without some critical interpreting and from which the creationist as opposed to the clinitian is likely to procline.Edited by Brad McFall, : letter "u"Edited by Brad McFall, : small errorsEdited by Brad McFall, : spellingEdited by AdminJar, : No reason given.

Thanks for that particular information. This closes off some of the questions I had had in the first thread on the "human" tail I linked in this thread. I think that I was most impressed by Simpson's use of the word "throw-back" (in an issue that Gould misread at first as a young up and coming something)but as you can see the notion of atavism came up in the first thread on this topic. I did not participate much as the question went quickly to frog eyes rather than primate tails.Although all of the thoughts and data are not in ( I saw some claims on the web about humans having mouse genes for tails or at least that was the implication but I could not find anything but a few hyped sentences so far, which seemed no different than Gould's older useage of "regulatory gene hierarchies") it seems that the thread has moved off any potential disagreement between you and I, on the fully historical-functional side as illustrable by Gould's figure 10-10 below ( I have labeled where I am guessing the difference between us lies, but is is only guess).That kind of placement was my intention, at least so far in representing the creationist position, for if one takes ANY angle from the left horizontal towards the historical as Gould had it there would be NO WAY that a creationist position could be true. There still might be a black and white difference among our contributions though not digramable as I have highlighted a difference if there are rigid positions on the INTENT of the difference between homology and homoplasy. This might not come up for us however or anyone else who wants while participating in this thread to place their name in the traingle.
If you think this use of Gould's figure is a little premature, a simple indication such, will have me work out a more extensive critical position.

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Edited by Brad McFall, : removed extra url reference

woah there EQ.Hindsight is always 20/20.I was lead to stress the current use of Human Tails because of the wording Bernd created in the FIRST POST in this thread.You allege "illogicy" but I feel burdened to render completely logical ALL MY POSTINGS together on EVC. In this case I was starting out to have to aver my own sense of my lack of posting in the earlier thread on "tails." What you call "unduly" complicated is really an example of how involved THE WORK of creationism can be to extend evolutionary thought. I have not gotten to this part in this thread as of yet. Bernd seems to realize and understand this and is patient beyond a daily internet "fix." Look if Bernd had not posted that he was OK with my situating a difference between him and me then I would have to re-write from a backward discussing inclination. The complexity of my posts start out this way to ensure I can get to the parts that I would need to if I am misunderstanding who I am posting to. It is just courtesy. I am feeling very bad from Robin just now, so I am not in the mind to carry this conversation further today.You say that it doesn’t matter what the human tail means for humans today but if you would wait for the discussion on cell death IT WILL MATTER as to how far the "structuralist" component is relevant. I sense instead that you would feel that one should be arguing more purely for a heritable complex allele mutation that natural selection caused which I feel, despite or due to the complexity of my inveighing herein, I think I need no longer address.Do you really "get" the Point of my post?Here is a quicky of where this thread is going for me. Gould divided nationally, formalism and functionalism in biology but within the current evolutionary use of homoplasy he did not work out for his own conceptual system the possiblity that a MORE FORMAL AND MOLECULAR view could render his notion of "clumped morphospace" NOT dependent on (Platonic) archetypes.This same intellectual Pavloffianism shows up in pure math as well, when addressing sets. Only in biology there is no simple way around Aristotle as there is in theology. I read biology BEYOND the simple words TO THE FORMS of creatures themselves, so in the end it is the organisms that dictate, no matter how hard I try to retrodict. Once I get "all complicated and the like" it is usually fairly easy for me to imagine from that place a given creationists complaint. It was Bernd not me who suggested Cell Death in this case and if you look a little bit at the pages I copied about ideas on the origin of cell death this is going to make the case in general for the tail being a clear result of heritable homology harder not easier to maintain as the LEVEL of the cell's causality will needed to be worked in, independently of the genes or the organisms or the populations. This is what hierarchy is all about. So unless you reject hierarchicalization out right meaning it is all out "wrong" then I do not understand how you can lay claims of illogicism and unfortunate complexity to my contributions on or off the page.This thread is really going somewhere. Let's not let the rest stop and may Robin rest in peace, stop, the rest of us. All the best, Brad.

Here is short way through a thought process whereby "human tails" may be functionally-structural only and NOT an aspect of history. This is an overview of the reasoning. There is no reason that data can not falsify the claim. Thanks for being patient. I dont want to wait and have a misplaced hype for a response.Gould argued twice in "Structure of Evolutionary Theory" that Dobshansky misrevealed the nature of Wright's adaptive landscape by trying to attach ideas of "ecological topography" at the species level which Gould sustained were wholly due to history. This is comparable (so it seems to me but redirect me if you disagree)to your query as to how it could be claimed that the tail phenotype in humans is NOT due history.Thinking like Dobshansky and not like Gould, I would suggest that creationists attempt to interpret the notion of harmony (peaks)and disharmony (pits) in Wright's ideas (between gene combinations in individuals subject to being the grave or vehicle phenotype of cell death continuity which can be structural as to gene frequecies in populations). Thus the species of apes are on peaks that only the grave of cell death crosses doing so by "datamining" disharmonious concatenations and thus abberant formal (form)spaces. The gene combinations of cell death vehicles survive this transit but these being in terms of cell lineages do not constitute history (deme vs species)but only the ordered topology of embryogeny and thus subject to the neurulation idea and the sum of graves WITHIN the apes.I can add the quotes from Gould and Wright and Dobshansky and Ameisen if these would be helpful. I am thinking that the "harmony" of multiple leveled peaks to "mountain" ranges depend on canalization while the depth of the disharmony, disturbed by disequilibria contrarily have no bottom diagrametically. Here actual cell death histories compete with molecular manifestations. It seems that it is failure to notice that there is an "upper bound" to the peak but no "lower bound" to the valley that had continued to frustrate interpreations of the "adaptive landscape" as Wright intended the "phenotype." Cell death certainly populates the "deserted and empty" valleys of Dobshansy's Wright but harmony is only subject to equilibria not non-linearlity and non-equilibria (except by pure natural selection and we had moved from that point in the conversation). I think that cell death speculations tend to make this interpretation easier even though Amiesen's best ideas are interms of geneic selectionism only (toxic vs nontoxic bacteria).The result will be that the peak range of Apes is one without tails but that the pits never result in "underground" connections to a different set of peaks with tails (as in monkeys) but only that chance expressions and surviving cell death graves can get to a "caudal appendage." This would overdetermine a possible "kind" in baraminology as well I would guess. Cell death vehicles do not travel in this space even if they do for other mammal clades that contain tailed and nontailed grades.This is the general idea. I looked quickly at your links about cell death and the vertebrate tail. I do not think there will be any ideas in these papers that can not be contained by the above analysis. If you think there are please let me know.This idea would be wrong if the regulatory genes for tail expression was found conserved as in hox genes for general segmentation. It is also possible that some aspect of hoxology may disrupt my structural prescription for which I was trying to take more time to figure out. I wanted to get the general stages in the argument out however even if I am completely off base here. So that others can do some of of the surfing as well.Edited by Brad McFall, : No reason given.

It seems to me that the entire issue of to detail or not to tail, has to do with this picture below:

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Gould wrote (SETH p 1030)about it in terms of cats and dogs but he went to flying zebras(as I shewed earlier in this thread) instead of working out an angle of allometry that appears from symmetry in clades expressed in a prior time of biological study phyletically as: as snout/lower jaw shortening in bears vs. longer nose/heads of haeyneas.

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Gould wrote it that way because of how Collin Tudge
covered "carnivores"(notice placement of "tails" in the clade diagrams).

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other non-quoted clade diagrams from Tudge

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But from the pictures alone one can observe that there are only words making the differences. Premeditation about flying zebras or gate differences when other allometrics might be causal seems gratuitous to me.I still retain the ability to write of top to bottom mammal allometry(effective in issues of locomotion) but I take a different view of "punctuation" or "catastrophe" or saltus"" than Gould. Working in the issue of cell death makes this a much more complicated undertaking.

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Structure of Evolutionary Theory by SJ GOULD page 922 with my own supplement

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Edited by Brad McFall, : spelling and grammarEdited by Brad McFall, : restoring last comment deleted during edit

Ok, let's see...Is colinearity to be thought equivalent in insects/arthropods as in vertebrates?Gould was conscious enough to notice that it might not be the case that the simple use of fly probes to find frog hoxes was more than a hoax (SETH page1102

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The initial discovery of homology in genetic structure of arthoropd and vertebrate Hox did not seal the case for evolutionary meaning, since no one yet knew how vertebrate Hox genes operated.

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Only one sentence later Gould said,

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Evidence for similarity of action soon followed, thus securing the argument for...

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What "action" was secured?

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The established rules of "hoxology"* vindicated the central principles of morphogenesis in Lewis's model.SETH page 1099

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This principally was:

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Lewis's model neatly explained the most famous and puzzling homeotic transformations, both based on loss-of-function mutations. Bithorax., the celebrated four-winged fly, does not represent an atavistic reversion to the ancestral state, but arose by a weaking of the gradient that caused the third thoracic segment...

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Gould (SETH 1099)quoted,

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As Warren et. al. (1994, p.461) write: Hoxgenes "provided a pre-existing groundplan upon which insect segmental diversity evolved."

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Gould concluded (SETH 1100)

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The perfect colinearity of spatial order along the chromosome with the sequence of morphological differentiation along the developing animal's antero-posterior axis summarizes the most stunning conclusion of this research, and also generates most other hoxological regularites

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Gould went so far as to say (SETH 1100 ),

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The ultimate loss, a fly developing with noHox gene function at all, leads to lethality, with the dead embryo as a grim and facinating manifestation of expected rules: a misfit bearing antennae on each of its segments (Shubin et al., 1997, p644).

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Do we see vertebrates with gain-of-function mutations having tails in the place of analogous arms and legs?Could it not be that the is NO "colinearity" in the sense pre-existing but only a discrete "vectors" between ordinally different topographies from chromosomes not a morphogenetic gradient?Gould's presentation of Hoxd-13 praises the author "Dolle'et al.s'" "conscious linkage to classical data on heterochrony (SETH p 1103) but via a conscious reciprocation to gain-of-function mutations there are no "tails" extending from vertebrae but only ribs and lateral projections from segements more anterior than tails.

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"Structure characteristic of more posterior vertebrae", "pair of ribs..."

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I can tell you quite confidently, but it would take some time for me to document it that the word "anlage" is ambiguous in the technical literature of squamate morphogenesis. So the phrase "elongating" 'anlage' in you review article CONTINUES to raise some mental concern on my part, ie when one is only observing ecotypic expressions in misplaced somites. The word "vector" rather than "gradient" seems more consciously appropriate here, where, one does not deal with the the discontinuity between linear order on a chromosome and spatialization FROM that linear order(you could note that in a short page of text Gould uncharacteristically moves from the word "read" to "write"(Seth page 1099 (dealing with ?wolpert's notion of positional information)). It is not clear to me that the so-called 'segmentation' is not really a scalar magnitude only.Thus if the reading of hoxology requires a vetor field rather that an gradient IDENTICAL to 3'-5' transcription direction we have only a co-ordinate system or inertial frame of reference at best to extend the somite variation developed into the clades of monkeys vs apes. I am not sure this is enough data to gain the function of a tail historically homogenously throughout the primates. Notice also how with respect to insects Gould displaced the historical explanation FOR THE MATHEMATICAL (but not physical) configuration of a gradient (a line). He went on to sustain this based only on "geometric duplication" when discussing from the old Lewis model to actual hoxology(SETH 1096-1098).I am guessing, and this can be a good test, that reading through in detail on Wnt3-a substituting the word "vector field" for "gradient" will not disturb the experimental predications and results.Do you work with Wnt3-a?I will add the quotes for a prior post and more about my own position in a next post as well as working up how I guess now, BOTH clock and gradient need not necessarily be an issue for chromosome linearity where an inertial system rather than a simple chemical gradient theorizes the formations format. Sorry I still have not downloaded an uptodate PDF reader.