Scrub jays too weird for Wired mag?

_{Denyse O'Leary

March 13, 2015

Darwinism, Evolution, News}

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That’s, like, weird. From Wired:

As she gathered more and more data on different populations of the birds around the island, Langin had a revelation: The birds, members of one single species, had split into two varieties in different habitats. Island scrub jays living in oak forests have shorter bills, good for cracking acorns. Their counterparts in pine forests have longer bills, which seem better adapted to prying open pine cones. That may not appear to be something you’d consider a “revelation,” but it really is—if you believe in evolution. Ever since Darwin and his famous finches, biologists have thought that in order for a species to diverge into two new species, the two populations had to be physically isolated. Those finches, for instance, each live on a different Galapagos island, where their special circumstances have resulted in specialized bill shapes. Yet the two varieties of island scrub jay (they haven’t technically speciated—yet) live on the same tiny island. If they wanted to meet each other for a brunch of acorns and/or pine nuts and perhaps later some mating, they could just fly right over.

This is very, very weird. It’s an affront to a sacred tenet of evolution you probably learned in school: Isolation drives speciation. Well, speciation can also come about in a broadly distributed population, with individuals at one end evolving differently than individuals at the other, but nothing kicks evolution into overdrive quite like separation. Without it, two varieties should regularly breed and homogenize, canceling out something like different bill shapes (though rarely the two types of island scrub jay will in fact interbreed). And the island scrub jay isn’t alone in its evolutionary bizarreness. In the past decade, scientists have found more and more species that have diverged without isolation. Langin’s discovery with island scrub jays, published last week in the journal Evolution, is perhaps the most dramatic illustration of this yet. More.

Okay, first, knock out the bong pipe. Shower and put on some shoes. Have a look at the job board.

Darwin was wrong about everything except the fact that you could make a living somewhere, high in California. Turns out you can. About the rest, we dunno.

The birds had to be smarter than you. Not so hard.

By the way, all that Darwin’s finches stuff is nonsense too.

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Comments

Why paper did you find mistakes in and what were the mistakes Timaeus?Curly Howard_{March 29, 2015
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Zachriel: One such mechanism would be the self-engineering of the genome by the organism. Others would be found in the "structuralist" biological literature; I cannot give you instant article citations, which I don't have at my fingertips, but there are many books and articles out there by Stuart Newman, Gunter Wagner and their associates which lay out some "functionalist" possibilities, related to innate mathematico-physical-chemical structures within living nature. You are intelligent enough to use a university library to find both books and articles by these authors, and if you have free access to the journals you can download and read the articles at will. And of course it goes without saying that any presentation of evolutionary theory, like any presentation of physics or chemistry, has to be written at a level appropriate to the student, so please don't bother making your point about material that is "too hard" again. The technical articles of Ernst Mayr on neo-Darwinism are also "too hard" for ninth-grade students, but that doesn't stop simplified versions of his neo-Darwinism from appearing on the curriculum; the same is true of any evolutionary mechanism; all can be put in simplified layman's terms for younger students. I don't intend to go into more detail than that here, as I'm terminating my overly-long involvement with this thread. But if you are interested in some high-level discussion of evolutionary theory that is somewhat different in orientation from what you are accustomed to, you will look up the authors I've suggested (and the sources which stimulated them), and learn what they have to say. I think people should read books and articles about evolution (or any subject) to learn, to expand their understanding, to take intellectual risks (including the risk of having to abandon or reformulate many cherished theories and notions), not to find ammunition to use in arguments. Unfortunately, too often, when the subject is evolution, the only reason why people read anything beyond their immediate "camp" is to find a way of refuting someone else. Thus, debates over evolution tend to be not explorations where different points of view are discussed with an open mind and then synthesized, but are more like a form of trench warfare, with each person "dug in" and holding the line at all costs. This is very sad.Timaeus_{March 29, 2015
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Piotr: Yes, that is a good discussion, and I see your point about the term "body plans." Really the major point I was raising could be made without the reference to "body plans" -- it was only because Curly claimed that I had made an error that we have let the terminology derail the discussion. The question I was raising was whether neo-Darwinian mechanisms alone could account for the remarkably quick transformation between artiodactyl and whale. Many evolutionary biologists have answered: "No." And they have explained such dramatic evolutionary changes in terms of different approaches, such as evo-devo. But the popular mind still has a primarily neo-Darwinian conception of evolution, and that includes many big-time champions of evolution such as Ken Miller and Richard Dawkins. If the popular conception changes, due to the writings of people like Carroll, so much the better. And there are others to be considered as well. Of course I recognize that it doesn't have to be all or nothing; neo-Darwinian explanation may have a place alongside other kinds of explanation. Indeed, even Michael Behe thinks that neo-Darwinian explanation is perfectly valid in some cases: antibiotic resistance, finch beaks, etc. He just doesn't think it's the whole story, or even nearly the whole story. My complaint about popular and textbook descriptions of evolution, even where they grant some non-Darwinian types of explanation, is that the Darwinian is still seen as the main engine of evolution, with the "other mechanisms" as ancillary (as if the army of Nazi Germany were aided by the army of Liechtenstein and of Moldova); but there are biologists who would tend to reverse that weighting, with the neo-Darwinian mechanisms in the back seat, doing bits of detail work here and there, and other mechanisms in the driver's seat, driving the major changes. Of course I would not expect an introductory high school course to go into this kind of material in any detail. I just don't want the students to come away with the invalid argument that if the giraffe's neck can be explained by neo-Darwinian mechanisms, so can the transition from artiodactyl to whale. That simply doesn't follow. All I want the students to hear is that plenty of evolutionary biologists -- including atheists -- have said that macroevolution cannot be explained simply by neo-Darwinian micro-stuff extended over a longer period of time, but involves other ways -- many debated, and many unknown -- of generating new biological form. But of course, as I've granted all along, that has to be said at a vocabulary level suitable to the high school grade being taught. And now I want to let this subject go. We've been at it too long. Let's find something else to talk about.Timaeus_{March 29, 2015
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Piotr:
I don’t personally attach any particular importance to the concept of “body plan” or “body pattern”, simply because it can’t be defined in an objective way.
That isn't true. Just look at Linnaean Classification. Also there isn't any evidence nor way to test the claim for changes in regulatory sequences can produce the changes required. Everything points to the contrary. Strange that Piotr talks about objectiveness from one side of his mouth but disregards it when it comes to universal common descent.Joe_{March 29, 2015
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Timaeus, I don't personally attach any particular importance to the concept of "body plan" or "body pattern", simply because it can't be defined in an objective way. Whether it's "major" or "minor" is a matter of taste. In metazoans, body plans are shaped by the Hox genes, but modifications appearing in different animal lineages (as the Hox family grew and their regulatory activity became more and more complicated) have been gradual, accumulating over time. Imagine two modern organisms, lets say a dog and a starfish. Let's assume, for the sake of the discussion, that their evolutionary histories separated some 600 million years ago, and that the separation was accompanied (or perhaps even caused) by some homeotic innovation. So 550 million years ago you have a proto-dog looking like a small fish, about an inch long, still with no bones, no jaws, and no paired fins, but otherwise with a general "vertebrate body plan" (a head with a tiny brain inside, gills, a notochord, etc.). At the same time you have a proto-starfish, a seafloor-crawling critter a few milimetres long with a bilateral body plan (unlike starfish proper, except in their larval stage), with an anterior mouth and gill slits not found in their later descendants. In a way, it already had the "echinoderm body plan" consisting of parts homologous to those found in starfish, but it wasn't all that different from the "vertebrate" plan -- not surprisingly, since both were derived from a common ancestral "deuterostome body plan". There were early deuterostomes such as vetulicolians and vetulocystids, which looked both like primitive chordates and like primitive echinoderms (so that their exact relationship to both phyla is hard to resolve).Piotr_{March 29, 2015
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What is surprising is that small changes in the genome can drive development of appendages nowhere near normal development sites.
That isn't surprising at all given what we know of regulatory circuits in our designs.
It was just an example of the drastic consequences on body plan that small genomic changes can have.
That was never in doubt. Look, your claims cannot be measured. No one knows how many mutations it would take or if any genetic change can do it. All you can do is hide behind Father Time as if that helps you. The problem is there aren't any known microevolutionary events, those small changes, that can be extrapolated into the large changes required. And thanks for ignoring the peer-reviewed paper that refutes your position.Joe_{March 29, 2015
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Timaeus: Does the standard curriculum include the kind of “other mechanisms” proposed by Shapiro, Newman, and Wagner? What specific mechanism did you have in mind? A scientific citation would be helpful.Zachriel_{March 29, 2015
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You mean highly inbred farm animals often have defective abnormalities? Is that a surprise? No. What is surprising is that small changes in the genome can drive development of appendages nowhere near normal development sites. The animal does have a different body plan, and whether it is no good or good is up to the environment. The legs/antenna example doesn't have a specific evolutionary significance as far as what has happened in the history of life. It was just an example of the drastic consequences on body plan that small genomic changes can have. Now you want a stepwise molecular-genetic explanation of the evolution of whales over millennia. This is the underlying problem that you and creationists have: you're not satisfied until every single step has been spelled out for you. You can use "body plan" however you want, but that doesn't mean you understand the idea. You're ignoring the fact that everything in biology exists along a spectrum. Rarely is there a definite cutoff point for anything, and therefore your use of "body plan" to mean ONLY large scale changes on evolutionary timescales, was wrong. What paper did you find mistakes in and what were the mistakes? I'm curious.Curly Howard_{March 29, 2015
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Zachriel: Does the standard curriculum include the kind of "other mechanisms" proposed by Shapiro, Newman, and Wagner? If so, then I have no problem with it. But I doubt very much that it does. Link me to some pages of state-accepted biology texts online, if you know of any, and I'll have a look.Timaeus_{March 29, 2015
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Curly: You say a number of foolish things. "and the studies I mentioned showed that these smaller changes in body plan are easier to come by than had been originally thought." I gather you are a city slicker. Farmers who raise thousands of animals during their careers quite often see defective offspring. So one doesn't need studies conducted by Ph.D.s in biology to know that such things can occur. Nobody but Curly "originally thought" that such changes were hard to come by. At the same time, the farmer, on seeing his two-headed cow or three-legged lamb, doesn't say: "Oh, how interesting; this animal has a different body plan from its parents!" He says: "This one's no good!" He thinks of it as the failure of execution of an existing body plan, not the success in execution of a new one. You say: "I did not claim that the legs/antenna example has any specific evolutionary significance." Well if such freak changes don't have any *evolutionary* significance, then why did you introduce them into my discussion of the *evolution* of new body plans??? Obviously I was talking about the body plans which are arrived at *by an evolutionary process*, not bodily deformities arrived by a reproductive error. But your more basic problem is the typical problem of the internet Darwinist. You try to "catch out" the other person on a point of vocabulary or by citing some isolated point of fact, while avoiding the big issue the other person is discussing. Instead of getting hung up on precisely when the term "body plan" becomes appropriate, why not focus on the obvious meaning of what I was getting at? I gave a very clear example: primitive artiodactyl to whale. I said that no one could explain in stepwise neo-Darwinian terms, *at the molecular-genetic level*, how that transition occurred. I don't need the term "body plan" at all to express that point. (I used "body plan" because I thought you would use the same definition that most people use, but since you don't, let's leave it out.) So, what is your claim, then? Are you saying that freaks like antennapedia have evolutionary significance (contrary to what you've just indicated) or not? If you say yes, then are you saying that it is thousands of little changes like antennapedia that turn artiodactyls to whales over time? And if you say no, then why introduce antennapedia to explain artiodactyl to whale? Why not talk about other, non-freak types of change? You aren't being very clear at all. All this started, of course, because you accused me of an error. In fact, what you call an "error" turns out to be nothing more than a disagreement over the meaning of "body plan." According to you, any visible distinction means a different body plan. But of course, very clearly the context of my discussion concerned major changes, not trivial changes, to the body. The various species of deer are visibly different, but most of them have the same basic body plan. The African and Indian elephant are visibly different, but both have the same basic body plan. The fruit fly with the leg in the wrong place is visibly different from his non-freak brother, but both have the same basic body plan. That's how I'm using the term. I made no error. You merely cavilled over my usage, and called it an error, and then decided, based on my alleged error, that I knew nothing about biology. By the way, I don't claim to be a professional biologist, and never have; but I've shown from the level of my discussions on this site for over 6 years now that I do have some knowledge of evolutionary theory; whether or not you acknowledge this is no concern of mine. I once found some biological and chemical errors in a work of evolutionary theory by a molecular geneticist; I wrote to the man in question, and he said I read very carefully and that I was indeed correct about the errors. So I know what I'm doing, at least in some areas of biology, and if you don't think I know what I'm doing, I'm not going to lose any sleep over it.Timaeus_{March 29, 2015
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Piotr: Your remarks about starfish and Hox genes, which I don't object to, pertain to the sort of discussion we get in evo-devo; classical neo-Darwinism knew nothing of such things. I already mentioned that evo-devo discoveries provide much more plausible evolutionary scenarios than classical neo-Darwinism. But of course, the question where all these handy kingdom-wide and phylum-wide and class-wide modules come from needs to be asked.Timaeus_{March 29, 2015
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Piotr: Thanks for the references. Only one of them seems to directly claim that a single deviation automatically makes a new body plan. The others seem to make statements that imply that single deviations *can contribute to* new body plans -- which is what most evolutionary biologists in my experience normally say. But never mind what others say. I want to know what *you* would say. Suppose you had never heard of me or UD or this argument we are having. Suppose a stranger on the street walked up to you and asked you the following questions. What would you naturally and spontaneously answer, using words as you would normally use them, not guarding yourself in any way?: A fruit fly grows a leg where normally an antenna would be. Nothing else is different about the fruit fly. All the rest of the anatomy, physiology, habits, etc. are identical to those of other fruit flies. Would you say that this fruit fly has *a different body plan* from a normal fruit fly? If the same fruit fly had five legs instead of six, i.e., if one leg failed to grow in, would you say it had *a different body plan* from a normal fruit fly? If a cow was born with two heads, would you say it had *a different body plan* from a normal cow? If someone had no wisdom teeth, would you say that person had *a different body plan* from someone with wisdom teeth? If a man was born missing an arm, would you say that he had *a different body plan* from two-armed people? For that matter, if a man had his arm cut off in an accident, would he from then on have *a different body plan* from two-armed people? If you would answer the last two questions differently, why? What is the difference whether an accident is internal and developmental or external and induced by violence, if the end result is a body with one limb less?Timaeus_{March 29, 2015
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So supporting my claims is deluding myself? How does that work? Anyway, coming from an ignorant ass like yourself, that is a compliment.Joe_{March 29, 2015
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Did you have a point?
Yep. You are good at deluding yourself.Piotr_{March 29, 2015
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Piotr:
Dogs and starfish, by the way, are not so distant from each other in terms of their Hox gene clusters and their functions.
Their Hox genes share a common design so that explains it.Joe_{March 29, 2015
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Piotr chimes in:
Here’s an idea. Bet Curly Howard $10,000 that you know more about biology than he does. You know what to do next; you’ve rehearsed it before.
Yes, I won the bet by supporting my claims and my opponent won't pay. Did you have a point?Joe_{March 29, 2015
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#250 Joe, Here's an idea. Bet Curly Howard $10,000 that you know more about biology than he does. You know what to do next; you've rehearsed it before.Piotr_{March 29, 2015
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If I am wrong, please quote me the evolutionary biologists who regard the fruit fly with the antennae or legs in the wrong place as having a “new body plan.” Otherwise, yield the point that Curly has confused two different things.
http://www.nature.com/nature/journal/v325/n6107/abs/325816a0.html http://www.nature.com/nature/journal/v473/n7345/full/nature09977.html http://www.nature.com/nature/journal/v415/n6874/full/nature716.html Dogs and starfish, by the way, are not so distant from each other in terms of their Hox gene clusters and their functions. http://learn.genetics.utah.edu/content/variation/hoxgenes/Piotr_{March 29, 2015
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insipid troll:
I did not claim that the legs/antenna example has any specific evolutionary significance. What this research showed is that small changes in the genome can alter body plan.
That was never in doubt. You need to be able to alter it in a way that helps the claims of your position. You FAILed. What you did was provide evidence for John McDonald. As we have said you are one desperate and deluded TARD. You walk around with your head up your arse but that also is not a good example for evolutionary change to existing body plans. Evo provides evidence that changes in regulatory sequences can cause deformations in body plans that would never get advanced in a population and calls us names for pointing that out. Typical, but still pathetic.Joe_{March 29, 2015
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"There is no change in basic animal structure" that is your opinion, Timaeus. I would argue the exact opposite. Apparently you think that someone born with legs growing out of their head is not significantly different from someone we would consider normal. I did not claim that the legs/antenna example has any specific evolutionary significance. What this research showed is that small changes in the genome can alter body plan. You may think it's an insignificant change, but that doesn't make it so. The large differences in body plans that we now see between distantly related species did not happen over night. Smaller changes to body plan occurred over time and the studies I mentioned showed that these smaller changes in body plan are easier to come by than had been originally thought. Both these one-shot changes and the changes that occur over millions of years are important in evolution and both alter the body plan. You had to throw in "which is dysfunctional" and you had to add "basic" onto "body plan" when you characterized my argument, but you shouldn't have. The antenna/leg example was not meant to model an evolutionary event that has occurred, it was simply meant to show how small changes in the genome can alter body plan. "Basic" or not, it is an alteration to the body plan. There is no small mutational change that will produce "a whale from a hippo-like creature." Those changes happen through smaller changes to body plan on evolutionary timescales. Again, just because you say the smaller changes are not actually changes to body plan, doesn't make it so. Generally speaking, a "body plan" is anything you can see just by looking at the organism. As usual, you are wrong on pretty much all counts. And Joe, you're an idiot.Curly Howard_{March 29, 2015
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Curly, I know more about biology than you ever will. And I am more than ready, willing and able to prove it. However that would mean that we are in the same classroom taking the same test at the same time. And I know you are too chicken to do that.Joe_{March 29, 2015
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As the standard high school curriculum already includes “factors other than random mutations and natural selection”, your concern has already been addressed.
Natural selection includes random mutations. And they have been found to be impotent. Perhaps the teachers should let the students know that.Joe_{March 29, 2015
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Piotr:
What about a dog and a human, or a sparrow and a snake, or an elephant and a goldfish? Do all vertebrates have a common “major body plan”?
Your position cannot account for any of them. Nice job. AGAIN:
Loci that are obviously variable within natural populations do not seem to lie at the basis of many major adaptive changes, while those loci that seemingly do constitute the foundation of many if not most major adaptive changes are not variable.- John McDonald, “The Molecular Basis of Adaptation: A Critical Review of Relevant Ideas and Observation”, Annual Review of Ecology and Systematics: 14, 1983, p77-102
Evidence, we haz it, you do not.Joe_{March 29, 2015
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Timaeus: “Evolution takes place due to random mutations and natural selection” yet say that they are incapable of understanding “Some biologists think there are factors other than random mutations and natural selection are involved.” As the standard high school curriculum already includes "factors other than random mutations and natural selection", your concern has already been addressed.Zachriel_{March 29, 2015
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Evos are so desperate. Putting a leg where an antenna goes does not help you. It is a deformity that would not happen in the wild and if it did it would not stay around.Joe_{March 29, 2015
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Piotr: Thanks for your answer. You ask the question about the boundary between major and minor body plan change. I don't see that this is any conceptually harder to handle than any other gradual change. A little boy changes into a man. The change is gradual. Yet only a fool would say there is no difference between a pre-adolescent boy and a fully grown man. Of course, I am not equating evolutionary change with changes in maturity in a developing organism. I am merely giving an illustration to make a point. My point is that one can legitimately declare that a final state Z is very different from an initial state A, even when one cannot pinpoint any particular spot (B, F, N, etc.) where one can say: "We no longer have an A but now have a Z." So if whales evolved from a hippo-like animal, even if we knew all the stages and all the causes, nonetheless we could see that the body plan has been drastically altered (albeit still within the vertebrate framework) in the transition. I call this drastic alteration a "change in body plan." So I don't see what objection you are raising to anything I've said. By contrast, look at what happens in antennapedia. Everything is identical between offspring and parent, except for the misplaced appendage. There is no change in basic animal structure; there is only an error which deforms the given structure. And unlike the changes in the mammalian body we are discussing in the case of whales, which on your account are all functional, the error in the fruit fly case is non-functional. At the very best it is neutral to the creature's survival; more likely it is harmful. And unless it is inherited, i.e., if it is merely a developmental error and not due to an altered genome, it will have no evolutionary significance. If someone were to play a Kuhlau piano sonatina incorrectly in two places, with a measure played in the key of C that should have been played in the key of F, and elsewhere with a measure played in the key of F that that should have been played in the key of C, with the effect of jarring the listener's ear in both places, would you say that the basic structure of the sonatina had been changed? Not if you know anything about the musical structure of the sonatina form! The sonatina form would remain in place, but its execution would be marred by two errors. So I am still right to say that Curly has things mixed up. He is equating an evolutionary process of stepwise but always functional changes which leads, over millions of years, to a new body plan, with a one-shot change which is dysfunctional and does not alter the basic body plan. If I am wrong, please quote me the evolutionary biologists who regard the fruit fly with the antennae or legs in the wrong place as having a "new body plan." Otherwise, yield the point that Curly has confused two different things. Regarding science education, I am fully aware that high school science simplifies things. I was a star student in science and went to university on a science scholarship. But you cannot have things both ways. You cannot say that ninth-grade science students are perfectly capable of understanding: "Evolution takes place due to random mutations and natural selection" yet say that they are incapable of understanding "Some biologists think there are factors other than random mutations and natural selection are involved." The two statements are on the same level of epistemological difficulty. All that I am asking is for the second sentence to be included in the ninth-grade curriculum, along with the first. One sentence! But Curly and Zachriel don't want even that one sentence in there. And they are making up all kinds of sheer B.S. for why they don't want it in there. But the real reason they don't want it in there is because they don't agree with it, because they think that all evolution *can* be explained purely by random mutations filtered by natural selection. If they would have the moral courage to be honest, instead of making up all kinds of crap about there not being time on the curriculum (how much time does it take to utter one sentence? or even one paragraph?), or by implying that alternate mechanisms would be too advanced for ninth-grade students to understand (when they are in principle no more complex than what neo-Darwinism proposes), I could at least respect them for honesty. I'm done with this subject, Piotr. I reject the excuses of Curly and Zachriel as motivated by a fundamental dishonesty, a dishonesty I have found in 95% of the internet Darwinists I have debated with. I will now accept no answer from them other than: "You are right; it would be possible, without adding substantially to the ninth-grade curriculum, to indicate that some biologists think there are factors other than random mutation and natural selection that operate in evolution; and if the names of Shapiro, Newman, etc. were mentioned in a footnote in the textbook, that would not harm any ninth-grade student in the slightest." But they are not man enough to concede even that. And that's because Darwinists are not men, but weasels. Speaking of changes in body plans!Timaeus_{March 29, 2015
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Questions to Wieschaus - fruit fly researcher - at the 1982 meeting of the AAAS:
Another questioner then asked Wieschaus about the implications of his findings for evolutionary theory. Here Wieschaus responded more soberly, wondering aloud about whether his collection of mutants offered any insights into how the evolutionary process could have constructed novel body plans. “The problem is, we think we’ve hit all the genes required to specify the body plan of Drosophila,” he said, “and yet these results are obviously not promising as raw materials for macroevolution. The next question then, I guess, is what are—or what would be—the right mutations for major evolutionary change? And we don’t know the answer to that.”4 Thirty years later, developmental and evolutionary biologists still don’t know the answer to that question. At the same time, mutagenesis experiments—on fruit flies as well as on other organisms such as nematodes (roundworms), mice, frogs, and sea urchins—have raised troubling questions about the role of mutations in the origin of animal body plans. If mutating the genes that regulate body-plan construction destroy animal forms as they develop from an embryonic state, then how do mutations and selection build animal body plans in the first place? [S.Meyer, Darwin’s Doubt, Ch.13 - The Origin of Body Plans]
Box_{March 29, 2015
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Timaeus,
Abandoning legs for fins, changing the shape and proportions of most of the bones in the body for aquatic life — those I call major modifications.
And yet they took place gradually. The forelimbs of protowhales were not "abandoned" and replaced with flippers overnight, nor did their hind limbs simply disappear. We have skeletons of early whales such as remingtonocetids, already adapted to a marine habitat, but still resembling modern otters anatomically. Modern cetaceans still have the same forelimb structures as their ancestors: the shoulder blade, the humerus, the forearm and palm bones, and four digits. The clavicle has disappeared and the fingers have some extra phalanges, but I don't tink you would regard these differences as "major". At what point would you say that a new "body plan" appeared? The evolutionary importance of saltational changes (as in the "hopeful monster" scenario) involving homeotic mutations, chromosomal aberrations, polyploidy, stable hybridisation, endosymbiont capture, etc., is the subject of debate, but some major transitions may well have been of this kind. When they happen in a relatively simple and unspecialised organism, they may occasionally result in sudden speciation without rendering the mutant inviable (to a lay observer, it would not even have looked dramatically different from the parent species despite carrying the seeds of a new "body plan"). As for telling students openly that nothing in science is settled forever and that there is much disagreement about the mechanisms of evolution -- I'm all for it. Handbooks are not catechisms, and differences of opinion are among those things that make science exciting. But to appreciate that, the students must first be able to understand what the controversies are about. And they are often about highly technical stuff that even professional biologists may not grasp fully. So one should go through the basic curriculum first, and then discuss examples of controversies. Those who are genuinely interested in the subject will probably be eager to read more on their own. (I'm saying this as the father of a biology student working for his MSc degree and doing research on some little-known marine phyla and the evolution of their enigmatic body plans.) Biology is not different from the rest of science. High-school physics does not prepare students for a meaningful discussion of the relative merits of superstrings and quantum gravity (but they are aware of the controversy if they watch "Big Bang Theory").Piotr_{March 29, 2015
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Piotr: I'm fully aware of everything you said in your summary of evolutionary theory. None of it was new to me. I've been round this park many, many times. Remember that I am not contesting common descent, so lists of intermediate fossils, etc. bore me. Send them to Ken Ham. I'm more interested in talking about alleged mechanisms. I do not consider number of legs to be a major modification. 32 or 36 legs, what's the difference to a millipede? Abandoning legs for fins, changing the shape and proportions of most of the bones in the body for aquatic life -- those I call major modifications. The discussion could get complicated unless we distinguish between classical neo-Darwinism and later notions such as those entertained in evo-devo. My critique is focused on neo-Darwinism because that has been the main public presentation of evolution until very recently, and is still the main conception of evolution in the minds of most of the lay public. I believe it is the conception held by Curly as well. Evo-devo is a different matter, because the discovery of universal genomic "switches" means that larger changes can manifest themselves more quickly. In classical neo-Darwinism things had to be built up from scratch, one new protein by one new protein, and unless islands of fitness could be demonstrated whereby partial eyes, partial wings, etc. were of some use in the struggle for existence, neo-Darwinism was simply not credible. Yet it was taught in the schools anyway, because *some* materialistic, reductionistic account of origins had to be given in the public schools; better an implausible materialistic account than any account, no matter how rational and in accord with evidence, involving design! (I will give you the benefit of the doubt and assume you know the difference between ID and creationism; if you don't, see my explanation to Aurelio Smith above.) Anyhow, I see the creation of a new pair of legs (and a body section to go with them) as Dawkins sees it: merely a command to "do it again!", i.e. do once more what has already been done in all the other segments. The "software" for segments and legs has already been written, so it's simply a question of activating it an extra time; nothing new has to be built from scratch. But that is more an evo-devo than a classical Darwinian perspective. (And I'm not at this point rejecting evo-devo; in fact, I would add Sean Carroll to my list of people who could be mentioned by a biology teacher or in a textbook, even in states where evo-devo is not yet on the prescribed ninth-grade curriculum.) Piotr, from what I have heard of you on the internet, you make claim (or others claim for you) to be a professional evolutionary biologist, actually researching and publishing in the field. Is that correct? Or if not, what background are you speaking out of? If you are in the field, and if you go regularly to conferences, read journals, etc., e.g., you will know of the annual Evolution conference which has thousands of attendees. If you go there, you will know that some of the biologists I have mentioned, e.g., Altenberg people such as Wagner and Jablonka, sometimes present research there. You will also know of their papers in legitimate scientific journals. You will know, then, that they are legitimate scientists and legitimate evolutionary biologists. You will also know that they differ in some respects with classical neo-Darwinism and even with some of the later developments in evolutionary biology. My contention *here* (on this page) has not been against evolution, or even against neo-Darwinism (though I have said elsewhere that in my view it is a weak theory), but only that high school science students should be made aware that, while there is consensus regarding common descent, there is not consensus regarding evolutionary mechanisms, and that there is lively debate among evolutionary biologists about mechanisms. I have not said that a huge amount of time can be spent on these mechanisms in introductory biology. I have not said that teachers should say neo-Darwinism is wrong. I have not said that textbooks should teach that Shapiro, Newman, etc. are right. I have said that students should be given an indication that there is debate over mechanisms. Curly and Zachriel have opposed my view on this. Do not be misled by their words (especially if you have come into this late and have not read the whole discussion prior to the point where you came in) into thinking I am arguing something more than I am arguing. Do you agree that at *some* point in high school biology (maybe not in ninth grade, but at some point) it is proper to inform students that there is disagreement among evolutionary biologists over evolutionary mechanisms? And to give at least a sketch outline of some of the different views held by evolutionary biologists on the question of mechanism? And would you be against a *footnote* in a ninth-grade text indicating the existence of differences over mechanism, with one or two references that a bright student could follow up on? Would you be against a teacher mentioning the existence of some differences over mechanisms? This is what I have been trying to focus on, but without success. But back to Curly: I am not contesting the claim that, according to neo-Darwinian theory, small genetic changes can eventually lead to major body plan changes. If you read the precise *original* statements of Curly that I objected to, and if you read my objection with care, you will see that what I was objected to was his implication: "See! An antenna appeared where a foot should have been! Darwinian processes produced a major new body plan!" This is simply a mischaracterization of what evolutionary biologists think. No evolutionary biologist on this planet would say that a fruitfly with a leg in the wrong place has evolved a major new body plan. They would say that a genetic copying error or a developmental error has occurred, and that, unless that error has found its way into the genome, it will not be replicated in future generations; there is no "major new body plan" in that case; only a defective fruit fly due to a biological error. Now, Curly later modified his claim to the claim that small genetic changes can *lead to* body plan changes (presumably after thousands of generations of cumulative small changes); but he originally introduced antennapedia itself, and other similar reproductive blunders, as examples of major body plan changes; and that is not how any evolutionary biologist I have read has used the term. If you think otherwise, please provide me with quotations and page numbers from evolutionary biologists who think that such freaks constitute major body plan changes.Timaeus_{March 28, 2015
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Piotr: Curly gave a good and valid example of how major modifications (e.g. the number and location of legs — arguably part of the definition of a body plan) can be caused by small genetic changes.
Unresponsive. No one disputes that. What is been disputed is that an extra set of non-functional useless wings - without muscles and nerves attached to it - on a fruit fly constitutes a "new body plan" rather than a mechanical error.Box_{March 28, 2015
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