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Jonathan Wells on the contemporary state of Evo-Devo

I asked Jonathan Wells to put together the following brief update on evo-devo.

A March 30 press release from the University of Bath quoted evolutionary biologist Ronald A. Jenner as saying: “Since its inception, some workers feel that evo-devo hasn’t quite lived up to its early expectations.”

This is an understatement, since evo-devo has not provided an experimentally confirmed explanation of even a single case of macroevolutionary change. Yet Jenner’s sober assessment contrasts sharply with the extravagant boasting of Darwinist Sean B. Carroll: “Evo Devo reveals that macroevolution is the product of microevolution writ large… We now have a very firm grasp of how development is controlled. We can explain how tool kit proteins shape form, that tool kit genes are shared by all animals, and that differences in form arise from changing the way they are used.” (Endless Forms Most Beautiful: The New Science of Evo Devo, Norton 2005, pp. 291, 295)

Maybe Jenner and Carroll should talk…

Most research in animal development focuses on six model systems: fruit flies, roundworms, frogs, zebrafish, chicks and mice. According to the Bath press release, Jenner doesn’t think these are enough: “Whilst this is generally fine in the context of development research, the benefits to evo-devo as a subject are limited… Instead, we urge workers to select new models specifically to illuminate hitherto neglected general themes within evo-devo.” Jenner’s co-worker, evolutionary biologist Matthew A. Wills, agrees: “Establishing criteria for choosing model organisms is important in this field, especially given the pressure on available funding sources. We encourage evo-devo workers to communicate with funding agents so that the limited resources available will not be disproportionately channelled to the ‘big six,’ which, while important, cannot illuminate all evo-devo’s central themes.”

It is clear from statements by Jenner and Wills that – like other Darwinists – they assume that all animals are descended from a common ancestor. Yet the very focus on a few models systems that they decry has discredited evidence for this assumption.

Darwinists have been telling us for years that some of the best evidence for the common ancestry of insects and vertebrates is their Hox genes, which affect the character of body segments during embryo development. For example, a mutation in one Hox gene can cause a fruit fly to sprout a leg from its head in place of an antenna. Remarkably, vertebrates possess Hox genes that are very similar to a fruit fly’s ¬– so similar that a mouse Hox gene can enable normal development in a fly embryo that lacks its corresponding Hox gene. More remarkably, the order in which Hox genes are lined up on the chromosome is the same as the order in which they’re expressed along the embryo’s body axis –¬ a feature known as colinearity. And most remarkably, colinearity is the same in the four Hox gene complexes of vertebrates as it is in the Hox gene complex of the fruit fly Drosophila melanogaster.

This striking similarity in Hox gene colinearity is often cited as evidence for common ancestry. For example, according to a widely used college textbook, “The ordering of the genes within each vertebrate Hox complex is essentially the same as in the insect Hox complex, suggesting that all four vertebrate complexes originated by duplications of a single primordial complex and have preserved its basic organization.” (Bruce Alberts et al., Molecular Biology of the Cell, Fourth Edition, Garland Science 2002, p. 1194)

Last year, however, seven different arrangements of Hox genes were reported in various species of Drosophila – all fruit flies, in only one of the six model systems mentioned by Jenner and Wills. Apparently, the arrangement in Drosophila melanogaster that so strikingly resembles the arrangement in vertebrates has not been inherited from a common ancestor but is a relatively recent acquisition. (B. Negre and A. Ruiz, “HOM-C evolution in Drosophila: Is there need for Hox gene clustering?” Trends in Genetics 2006, doi:10.1016/j.tig.2006.12.001)

So this showcase piece of evidence for the common ancestry of animals – one of “evo-devo’s central themes” – turns out to be false, disproved by analysis of only one of the “big six” model systems.

I guess if I were a Darwinist I would want funding to look at other systems, too.

Jonathan Wells, Ph.D.
Discovery Institute

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28 Responses to Jonathan Wells on the contemporary state of Evo-Devo

  1. This is unrelated. Does anybody know when Berlinski’s article on the origins of matter is coming out in Commentary?

  2. Very cool.

    One question though. You know the new stories of chimpanzees making stone tools and fashioning spears to hunt?

    Is this a hoax? Nearly everything I have read about it claims it is the real thing. If Chimps really can fashion spears and hunt, does this challenge the argument for design?

  3. My roomate just sent me this article.

    http://news.bbc.co.uk/2/hi/sci.....387611.stm

    Please read it. Does this finding conflict with the argument for Intelligent Design?

  4. What of the top-level ID acceptance of Common Descent? Is the front-loading hypothesis dead now?

  5. DN:
    If Chimps really can fashion spears and hunt, does this challenge the argument for design?

    No. Why would it? (just curious)
    ———————————-

    Phevans:
    What of the top-level ID acceptance of Common Descent?

    Accepatnce is a broad word. Why is Common Descent accepted? That would be the question to ask. Is it accepted on faith or is there a scientific basis for it? For example:

    What is the top-level data that demonstrates single-celled organisms can evolve into something other than single-celled organisms?

    And closer to home:

    What is the top-level data that demonstrates the physiological and anatomical differences observed between chimps and humans can be accounted for via genetic mutations?

    Answering those questions will demonstrate what that acceptance is based on.

  6. DN:If Chimps really can fashion spears and hunt, does this challenge the argument for design?

    No. Why would it? (just curious)

    The uniqueness of mankind, our highly complex linguistic capabilities and capability for abstract thought make us unique. At least I thought.

    Do you think this is threatened by Chimps making tools and hunting?

    I would like to know what Bill Dembski thinks about this story. I would love to know.

    Also Could someone please explain to me Dembski’s views on the creation of Homo sapiens?

    Much Respect

  7. sfg:
    The uniqueness of mankind, our highly complex linguistic capabilities and capability for abstract thought make us unique. At least I thought.

    We are unique. That other organisms use tools does not make us less so.

    I live in an area that has beavers. Their cunning, design and building ability are amazing. They survey the scene and figure out exactly what they need to get the job done. The precision and accuracy with which they drop trees rivals that of seasoned lumberjacks.

    They create their own ecosystem. Their lodges are another story.

    IOW for what they do, they do it better than some humans can do anything.

    And according to Doug Adams we humans are third on the depth chart anyway- behind mice and dolphins.

    sfg:
    Do you think this is threatened by Chimps making tools and hunting?

    For all we know this chimp behaviour was copied by watching human hunters in the area. And even if it was a something learned “de novo”, we know that chimps have been using twigs to root out termites and birds sometimes use twigs as tools.

    I still don’t understand what you think this means to ID. There isn’t anything in ID that states that chimps will never be able to use tools.

    What’s your point? Do you want to put them to work so they too can pay taxes?

    sfg:
    Also Could someone please explain to me Dembski’s views on the creation of Homo sapiens?

    Homo sapiens was created by Carolus Linneaus. Maybe Wm disagrees with that but I fail to see the relevance.

    I would love to know your answer to the following:

    What is the top-level data that demonstrates the physiological and anatomical differences observed between chimps and humans can be accounted for via genetic mutations?

    Perhaps if YOU opened up a little- ya know as a show of respect- Bill might also.

    Just a thought.

  8. sfg:
    I’m afraid I have no idea. That is why I am asking questions.

    And that is OK. That is why we need science- to help us answer those types of questions.

    But the point is humans exist and there is one reality behind that existence. So what we should do is to take that data- we exist- and weigh it against the possible options-> Common Descent via culled genetic accidents? Common Descent via front loading evolution? Special Creation of different populations? (or my personal fav) Colonization from some other planet- not merely panspermia?

    Now if biology/ genetics can’t or doesn’t help us with the first two (or refutes the first two) what is left?

    That is why it is crucial to follow the data and not be hoodwinked by any preconceived biases.

    And that is how it should be presented in science classrooms- that we don’t know but we have some ideas. However it is presented as we do know just not all the details.

  9. Joseph [10]

    “That is why it is crucial to follow the data and not be hoodwinked by any preconceived biases”

    Agreed.

    Without doubt, the most empirically driven perception of nature is typological. Albeit, species can and do evolve and many can be linked together through clear sequences of intermediate subspecies. But, above this level, the typological model holds almost universally.

    Each type (such as the flytrap) exhibits unique features which are not found in other types of organisms (even to their closely related cousins the sundew or pitcher). The reason for the distinctness of each type is, amongst other things, the absence of functional continuums by which evolution can proceed.

    It can hardly be denied that there is massive empirical support for a typological perception of nature, far more so than either gradualistic evolution or front loaded gradualistic evolution. Yet it seems many are not content with a theory that explains what we can see (abrupt appearance, stasis) and not what they want to see.

  10. Acquiesce:
    It can hardly be denied that there is massive empirical support for a typological perception of nature, far more so than either gradualistic evolution or front loaded gradualistic evolution.

    Unfortunately it is denied daily. However if people want to explore other options I say let them. But that does not give them the right to force “what they want to see” on to people who see what is there.

    There is only one reality to our existence. And only an open discussion of all possibilities will flesh it out.

  11. Acquiesce: Each type (such as the flytrap) exhibits unique features which are not found in other types of organisms (even to their closely related cousins the sundew or pitcher).

    To the naked eye, perhaps. The genetic similarities are enormous, and telling. Besides, there are far fewer examples of truly novel expressed features than there are similarities.

    I’ve yet to hear a definition of a “type” which has any kind of coherence (mind you, I’ve yet to hear any definition of “species” that did either)

  12. Phevans:
    The genetic similarities are enormous, and telling.

    What do they tell? Geez just look at the vole:

    The study focuses on 60 species within the vole genus Microtus, which has evolved in the last 500,000 to 2 million years. This means voles are evolving 60-100 times faster than the average vertebrate in terms of creating different species. Within the genus (the level of taxonomic classification above species), the number of chromosomes in voles ranges from 17-64. DeWoody said that this is an unusual finding, since species within a single genus often have the same chromosome number.

    Among the vole’s other bizarre genetic traits:

    •In one species, the X chromosome, one of the two sex-determining chromosomes (the other being the Y), contains about 20 percent of the entire genome. Sex chromosomes normally contain much less genetic information.

    •In another species, females possess large portions of the Y (male) chromosome.

    •In yet another species, males and females have different chromosome numbers, which is uncommon in animals.

    A final “counterintuitive oddity” is that despite genetic variation, all voles look alike, said DeWoody’s former graduate student and study co-author Deb Triant.

    Phevans:
    I’ve yet to hear a definition of a “type” which has any kind of coherence

    Perhaps the following will help (or at least be a start):

    The Current Status of Baraminology

    Abstract

    The creationist biosystematic method of baraminology has grown significantly in the past decade. Its conceptual foundations were discussed in the evolution/creation debates of the nineteenth century, long before Frank Lewis Marsh coined the term baramin in 1941. Currently, baraminology has been applied to dozens of groups, and the results of 66 baraminology studies are summarized and evaluated here. Though bias in group and character selection prevents firm conclusions, it appears at this time that Price’s suggestion that the family is an approximation of the “created kind” may be correct. Criticisms of baraminology from evolutionists and creationists alike can be resolved with further research. Whatever its future, baraminology is at present a useful tool for investigating God’s biological creation.

  13. Phevans [13]

    All organisms are genetically similar to some degree, and we would expect morphologically similar organisms to contain more genetic similarities. But while this might suggest they share a common ancestor, it certainly doesn’t prove it.

    Incidentally the sundew, thought to be the plant the venus flytrap evolved from, is genetically speaking farther away from flytraps than small tree monkeys are from humans – and humans and chimps differ at roughly 150,000,000 nucleotide positions.

    Moreover, there are many similarities in nature which do not owe they origin to a common ancestor, because the supposed common ancestor lacked the feature. In such cases we are forced to believe that such features evolved independently multiple times.

    Regarding your second point. It’s not a matter of how many novelties exist, but rather whether gradualism can account for those novelties. No one would doubt flytraps evolved from sundews if there were a complete sequence of intergrading forms leading from one to the another.

    Lastly, regarding my use of the word type. I think it’s perfectly reasonable to use this term. After all, no one can name a flytrap or a dog or cat, which is in any sense not fully characteristic of its type.

  14. The flytrap

    In his Origin of Species, Charles Darwin wrote: ‘If it could be demonstrated that any complex organ existed which could not have been formed by successive, slight modifications, my theory would absolutely break down.’

    A system which meets this criterion is one which exhibits irreducibility. By that we mean a complex system which cannot evolve gradually through functional intermediates because of the necessity of perfect coadaptation of all its components as a precondition to function.

    The venus flytrap (Dionaea Muscipula) is without doubt the most famous of all carnivorous plants. They are perennial (last throughout the entire year) and can live for two to three decades. The mature plants usually have traps averaging one to two inches long – they also produce flowers for pollination.

    The closed trap is shaped rather like a clam shell, with teeth (or cilia) lining the edges. Yet when the trap is open, the two lobes (many with red pigmentation which attract insects) are convex (bent outwards). If you look hard enough at these lobes, near the centre, you’ll see maybe three or four tiny trigger hairs.

    Flytraps produce nectar by glands found along the inner rim near the teeth. Insects are lured by this necter and unwittingly enter the trap. As the insect moves around inside, drinking the nectar, it invariably bends two of the trigger hairs or one hair twice within twenty seconds, which springs the trap.

    Immediately an mild electrical current runs through the trap – the cells on the outer walls of the lobes lengthen, doubling size in a split second. This in turn causes the convex lobe to rapidly reverse itself, forming a cavity, snapping the trap shut, and causing the teeth to intermesh – inprisoning the insect.

    The trap doesn’t close tight right away, this is thought to allow small insects to escape so the flytrap doesn’t waste valuable time and energy consuming an insignificant meal. Important, as it usually takes over a week for digestion and a single trap rarely catches more than three insects in its lifetime.

    Larger insects (such as flies, ants, spiders) which can’t escape will struggle and in so doing will stimulate the trigger hairs further, this causes a further growth response that forces the edges of the lobes together, eventually sealing the trap hermetically and forming a stomach in which digestion occurs.

    The flytrap then manufactures and secretes disgestive juices through glands on the inner surface of the lobes, including an antiseptic, which keeps the insect from decaying during the time it remains in the trap and also purifies prey that are captured. The digestive juice then dissolves the soft, inner parts of the insect.

    There are only two sorts of evidence for gradualism (orthodox darwinism) which don’t depend on actual observation of the process:

    1. That is, finding a sequence of intergrading forms (either living or fossilized) leading unambiguously from one form to another.

    2. Or reconstructing the intergrading forms hypothetically by providing an entirely plausible genealogy including all the intermediate forms and a thoroughly convincing explanation of how each stage of the transformation came about.

    Needless to say, we have no actual observation of the evolution of the flytrap, nor have we a series of living intermediates, nor fossilized remains of the intergrading forms, nor for that matter do we have any convincing hypothetical reconstructions showing a detailed series of transitionals.

    This total lack of evidence (freely acknowledged by those knowledgeable about insectivorious plants) is not surprising considering that three main actions comprising multiple components must arise simultaneously:

    1. The ability to sense the presence of an insect (trigger hairs). Incidentally, while the ability to differentiate between animate and inanimate is obviously important, it’s not a necessarily part of an irreducible design. Although one wonders how effective, and therefore of what selective value, the trap would be without this.

    2. The ability to capture the insect (electrical signal, acid growth, turgor pressure, growth by cell division, correctly shaped lobes to form a cage, and the correct number and position of teeth to intermesh. The speed at which the trap shuts (about 100 milliseconds) is also clearly important.

    3. The ability to kill and digest the insect (to produce and secrete the correct digestive fluids in the correct amounts to enzymatically digest cellular molecules into nutrients, antiseptic to kill bacteria along for the ride and the ability to hermetically seal to stop fluids from escaping and bacteria from entering.

    Furthermore, whilst Michael Behe’s delicately emptying his mousetrap (eew!) and even more delicately resetting it (you watch those fingers Mike) the flytrap, at the end of its digestive process, reabsorbs the digestive fluid and then reopens, awaiting its next unsuspecting victim.

    Insectivorious plants are just some of thousands of organisms which defy a gradualistic explanation. What selective value is a flytrap without the digestive enzymes? or trigger hairs? or cilia? Rather than being the driving force behind constructive evolution, natural selection works conversely to promote stasis by eliminating the useless intermediate steps.

  15. I too would like to know a little bit more about Dr. Dembski’s views.

  16. If this not the proper forum to be inquiring could someone please direct me to one that is more appropriate.

    Alot of stuff on the net is INCREDIBLY biased against Dr. Dembski.

    Does he accept guided evolution or front-loading? A view in which life develops according to a kind of blueprint? Or something akin to special creation in which God creates each individual organism in present time?

    No disrespect intended. Just want to separate the facts from the propaganda.

  17. To clarify my position as Joseph [15] appears to use type, baramin and created kinds interchangeably. I use the word type to express merely the fact that all around the organism lies discontinuity.

  18. Acquiesce

    I am confused. Are you a supporter of Special Creation?

  19. DN,

    Dr. Dembski has written a lot of stuff. He has his own website where a lot of this is published. I am sure he talks about some of his beliefs there so go to the horse’s mouth. I found the two Dover things very illuminating.

    The link is above but is

    http://www.designinference.com/

  20. DN:

    I would call myself an empiricist; demonstrable evidence is all that really interests me, although I do like the odd good logical argument and bashing orthodox darwinism whenever I get the chance – if only because it’s made itself such an irresistible target. As an empiricist I would opt for the typological perception of nature, as it doesn’t extend itself beyond available evidence into realms of faith.

  21. I read somewhere that Dembski proposed that God re-engineered an ape like hominid into a man. I think Anglican evangelical John Stott takes a similar view. Can someone confirm this?

    Actually this is the article.

    bFast
    01/15/2007
    8:38 pm

    The “common design”ers. (I believe Dembski holds to this view.) These guys suggest that one day the designer started with a previous work, and reworked a new species — humans. In this view there was clearly a first human pair — Adam & Eve.

    Please write back.

  22. Hello?

  23. DN,

    See: Christian Theodicy in Light of Genesis and Modern Science

    Why doesn’t God grant Adam and Eve immortality despite the Fall?
    ….
    A final question now remains: How did the first humans gain entry to
    the Garden? There are two basic options: progressive creation and
    evolving creation. In the first, God creates the first humans in the
    Garden. In the second, the first humans evolve from primate ancestors
    outside the Garden and then are brought into the Garden. Both views
    require direct divine action. In the former, God specially creates the first humans from scratch. In the latter, God introduces existing human-like beings from outside the Garden but then transforms their consciousness so that they become rational moral agents made in God’s image.

  24. Thanks Scordova.
    I hope you have a Happy Easter. :)

  25. Scordova.

    Do you think this story http://news.bbc.co.uk/2/hi/sci…..387611.stm
    of Chimps being able to create spears in hunt does anything to diminish the argument for Intelligent Design?

  26. DN,

    I believe animals are intelligent. More impressive than chimp spears are beavers manufacturing dams, imho.

    Animals are human-like by design. Many have emotions and thoughts and memories and hopes and fears. Many are, as far as I can tell, intelligent. That is not by accident, but was ordained from the beginnning.

    The concept of a lamb (both its life and its death) was foundation of the world, it was no accident.

    Therefore, in the scheme of things, chimps with spears does not diminish ID. It does pose difficult questions about animal intelligence. Are beaver dams the product of ID?

    Happy Easter.

    Sal

  27. From wikipedia:

    Beavers have been known to build very large dams.[2] The largest known was discovered near Three Forks, Montana, and was 2,140 feet long, 14 feet high, and 23 feet thick at the base.

    Now such a dam is what I call ID!

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