Another paper on “symbiotic speciation” by Donald Williamson is retracted

November 11, 2011 • 9:09 am

About two years ago, I called attention to a bizarre paper in The Proceedings of the National Academy of Sciences (PNAS) by Donald Williamson, claiming that the life cycle of Lepidoptera, with a distinct caterpillar and adult stage, was produced by the hybridization between an ancestral butterfly (lacking a caterpillar stage) and an onycophoran (a velvet worm, the presumed ancestor of the caterpillar). This was palpably ridiculous since DNA sequencing would have revealed such a strange agglomeration immediately.

As I expected, that paper was thoroughly debunked by several people, including Michael Hart and Rick Grosberg, and now carries no weight. It also shook up things at the journal, because the paper’s editor, Lynn Margulis, appeared to have violated editorial procedure by submitting only the good reviews and ignoring the bad ones. 

A site called RetractionWatch, of which I was unaware, has reported that yet another paper by Donald Williamson—one on the same topic—has been formally retracted.

Retraction Watch has saved the original article, which you can find here. Williamson’s thesis is that complex life cycles of animals, involving larvae that are very different from adults, involved the acquisition of foreign genomes through either symbiogenesis (engulfing of one species by another, as in the formation of mitochondria from nommed bacteria) or hybridogenesis (two completely different species hybridize, as in Williamson’s previously retracted PNAS paper). Here’s the abstract of the retracted paper:

My larval transfer hypothesis asserts that mature adults became larvae in foreign animal lineages by genome acquisition. Larval genomes were acquired by hybridizationwhen sperm of one animal fertilized eggs of another animal, often remotely related. There were no larvae in any phylum until the classes (and, in some cases, the orders) of that phylum had evolved. Since larvae were acquired by hybrid transfer, they are not directly related to the adults that metamorphose from them. The widely accepted classification that associates echinoderms and chordates as deuterostomes, and annelids and molluscs as trochophorates or lophotrochozoans, is flawed. Symbiogenesis, the generation of new life forms by symbiosis, accounts for the discontinuous evolution of eukaryotic cells from prokaryotes. Hybridogenesis, the generation of new life forms and life histories by hybridization in sexually reproducing animals, occurred at all taxonomic levels from species to superphyla. Not only were larvae acquired by transfer from foreign adults from the late Palaeozoic to the present, but also complex animals were generated from simpler ones by this process in the Cambrian explosion, and organ systems were transferred between remotely related animals. There are several types of evolution. Symbiogenesis and hybridogenesis are saltatory genome transfer processes that dramatically supplement the gradual accumulation of random mutations within separate lineages described by Darwin.

The problem, of course, as Hart and Grosberg (and others) pointed out in their critique, is that Williamson’s original hypothesis has already been refuted by genetic analysis: butterfly genomes should show significant amounts of DNA more closely related to onycophorans than to other butterflies, and they don’t.  That’s also the case for the present paper at all: no phylogeny supports the idea of larvae arising by symbiosis or hybridogenesis.

Williamson’s new paper has been not only retracted, but completely effaced: here’s what you get when you go to the article’s pdf:

And the journal’s editor, David Richardson, issued only a terse remark:

I am not willing to discuss this matter except to say that it did not involve any matter of wrong-doing by the author, simply that  a significant amount of the information in the paper closely duplicated that published earlier without sufficiently addressing previous concerns  about the significance of particular findings.

Can you imagine a similar retraction issued when a claim of theology was falsified?  It’s as if Albert Mohler admitted that he now denies the factuality of Adam and Eve in light of new genetic findings.

At any rate, this shows once again that the truth will out in science. And it also refutes claims by Lynn Margulis and others that hybridization and symbiosis are more than just important events in the creation of evolutionary novelty—as they were indeed for things like chloroplasts and mitochondria—but are ubiquitous, with that ubiquity constituting a refutation of the tenets of modern evolutionary theory.

36 thoughts on “Another paper on “symbiotic speciation” by Donald Williamson is retracted

  1. When I first saw the title of the post, I read it as “symbolic speciation”. Hey, maybe that’s the answer to the Adam and Eve quandary?

    Anyway, Williamson’s idea is intriguing, but as you say, obviously there would be a very simple litmus test to see if it was even plausible, and it fails that. Bizarre that he can keep pushing the idea after that…

  2. Can you imagine a similar retraction issued when a claim of theology was falsified?

    Yes, except that it was the falsifiers who were usually compelled to retract, through the application of a sufficient amount of condign violence. When the action of Inquisition is prefaced with the adjective Holy, truth will not out; iron will in.

  3. Retraction Watch is a great site– Its actually been a bit shocking to me at times (eg Macrophage-Vitamin D papers retracted).

    And PNAS really, really needs to get their act together. They also published an obviously bunk ‘XMRV’ paper that helped let that circus keep going longer than it should have… but it was submitted by a NAS member, so they could ignore whatever reviews and reviewers suggestions they wanted. PNAS needs to reform their submission policies and guidelines.

  4. as I already said at Oikos blog


    neither bizarre nor false are in the same category as fraudulent. Science usually has its mechanisms of self-cleansing (usually by ignooring such publications or debunking them) that render bizarre falsities unproblematic (reminds me of the auqatic ape). I also would prefer to say its facts ratehr than “truths” that decide such issues.

    1. They remain problematic for science and education outside of the in-group though.

      The aquatic ape is an excellent example, since it is still alive and sometimes even paraded as fact or valid theory.

      I wouldn’t call it a _large_ problem by any measure.

    1. @Ant Allan

      Against whom?

      A false hypothesis is not anti-science.

      I wouldn’t even count a fraudulent article as anti-science but as fraudulent science.

      Has science won against itself then?

      1. Against ignorance. A bad idea was put forward and rejected because it didn’t hold up. We have reduced the things we can believe falsely by one.

        What more do you want?

  5. If this article by Margulis is authentic (, then she has a real credibility problem. In it, Margulis endorses the so-called scholarship of theologian turned 9/11 truther David Ray Griffin. Every truther argument I’ve heard epitomizes the way theologians and conspiracy theorists practice their craft, where sound hypotheses are never posed, and anything close to a sound hypothesis is conveniently untestable.

    1. It is not a problem: she is now known as veritably nuts.* She joins the ranks of Shockley (eugenics) and others.

      I am sure you can find an alternative description, but general conspiracy theories and their believers _are_ nuts.

  6. If new species arose because of hybridization, how would we come to have such widely variant species in the first place with which to hybridize? Hence I can’t see how this theory would undermine the primacy of natural selection in evolution even if it were true.

  7. Re: My last post. Yeah, I realize that Williamson is not seeking to entirely chuck out natural selection – I was just reading an article on Lynn Margulis and I still have her words ringing in my ears.

  8. If two complex organisms did hybridize in this way, how many times would it have to occur before it would result in a viable organism? If this were true, wouldn’t we see at least a few examples of failed hybridization in nature, the same way that we observe many harmful mutations occuring compared to the relatively few beneficial ones? Who knows, maybe we’d get the odd crockoduck popping up.

  9. After reading most of Margulis’s writings and conditionally accepting her thesis, I was amazed at her journey into the 9/11 controversy. New evidence about her theories now forces me to re-evaluated her ideas and suspend my support until or if I get additional evidence. At any rate she feels she has been ignored and defamed in the scientific world and this may be a subconscious way to get even. Symbiogenesis remains an intriguing theory that helps answer the question of what seems to be rapid evolution of a punctuated equilibrium nature as offered by Gould. I will withhold my judgement of symbiogenesis pending further research. I may not like her personality but I love her original thinking. Who knows, she may still be able to make a significant contribution to our knowledge of evolution. I anxiously await.

  10. Lynn Margulis’s assertion is, I believe, that essentially all speciation is due to symbiosis. So the two successive speciation events that led (say) to the White-Crowned Sparrow, the Golden-Crowned Sparrow, and the White-Throated Sparrow in the genus Zonotrichia must each have been accompanied by a symbiosis event.

    Really? What on earth could the evidence be for that?

      1. Wow, considering you dive right through stuff I wouldn’t touch with level 4 biohazard equipment… I’m trying and failing to figure out just how rotten it must have been.

      2. Prof. Margulis has degenerated into a crank in here declining years. She is also an HIV/AIDS denier and has dabbled with Holocaust revisionists.

        1. OK, I can go with a symbiogenesis between crank and nut. The crank would be the juvenile form, I take it?

        2. All this weirdness about her is especially nutty given that she was married to Carl Sagan, who was seriously against such things. I wonder if that contributed to their separation.

      3. I wonder if they’ve written this book before?

        My wife found book by them called “Slanted Truths, Essays on Gaia, Symbiosis and Evolution” in a dollar sale (hard cover!), and thought I might be interested. It’s from 1997, BTW. I’ve not really read it, but scanned several chapters, and it seems rather parallel. I’ve had other books waiting that seemed more important to really read, and you’ve not made me think I was wrong about that.

  11. “Can you imagine a similar retraction issued when a claim of theology was falsified? It’s as if Albert Mohler admitted that he now denies the factuality of Adam and Eve in light of new genetic findings.”

    Though this is not directly related to the title of this post but somewhat to the above quote -Here is what happens when Bible “scholars” let the proverbial cat out of the bag:

    “Interpretation Sparks a Grave Theology Debate
    Apologist’s questioning of Matthew 27 creates theological war of words.”

    “A fiery debate has erupted over a leading Southern Baptist apologist’s questioning of Matthew 27. The question: whether Matthew’s reference to many saints rising from their graves after Jesus’ resurrection might not be literal history.

    The theological war of words, spurred by high-profile open letters and retorts on the Internet, has raised questions about the meaning of biblical inerrancy. It has also led to the departure of Michael Licona as apologetics coordinator for the North American Mission Board (NAMB).

    At issue is a passage of Licona’s 700-page The Resurrection of Jesus: A New Historiographical Approach, published in 2010 by InterVarsity Press.

    “Based on my reading of the Greco-Roman, Jewish, and biblical literature, I proposed that the raised saints are best interpreted as Matthew’s use of an apocalyptic symbol communicating that the Son of God had just died,” said Licona, former research professor of New Testament at Southern Evangelical Seminary in Charlotte, North Carolina. Licona voluntarily resigned from the seminary on October 4 after the print version of this article went to press.”



    This comment by Chris said…

    “As a result of Licona’s questioning of Matthew 27, apparently some evangelical scholars, most notably Norman Geisler, accused Licona of denying the full inerrancy of the Bible.”

    But wait, we New Atheist rubes are always being told that no one really holds to biblical inerrancy – certainly not biblical scholars.

    I’m confused……

    Please Ceiling Cat check out this story..

  12. Margulis’s increasing strangeness seems more sad than anything else to me. But I’d sure have expected better than this from PNAS in the first place.

    1. It is sad, indeed, and all the more so when young scientists (like myself) can’t catch a break in landing tenure-track jobs. Perhaps I should just start publishing outlandish woo, as that’s where the money (apparently) is.

  13. I have this idea washing round in the back of my head (I’m not a Real Scientist so I won’t dignify it by the name of hypothesis) about caterpillars and butterflies.

    Could they have once been alternating generations of a once non-metamorphosing species, that grew more and more like different species, and the generation from caterpillar to butterfly became simultaneously more and more asexual till it became the present amorphous pupal stage?

    Someone with more knowledge can tell me about what similar species do (moths?) and what the standard theory of the evolution of metamorphosis is.

    1. Indirect development–having a very different larval stage with metamorphosis to adult–characterizes all of the biggest insect Orders: lepidopterans (including moths), beetles, flies, ants, wasps, etc. It’s not clear (to me) whether it’s ancestral to insects as a whole, or was acquired later by the ‘advanced’ groups mentioned.

  14. a significant amount of the information in the paper closely duplicated that published earlier without sufficiently addressing previous concerns about the significance of particular findings.

    How is that not “wrong-doing by the author”? It’s not fraud or falsification, but double-publication has always been a scientific sin. The reviewers may have dropped this ball, but Williamson is not blameless.
    Conincidentally, yesterday I read an article by him in American Scientist a few years ago (pre-dating the PNAS thing) which, because not peer-reviewed at all (I think), is even nuttier. He’s claiming rampant hybridization of things like echinoderms and tunicates, rotifers and annelids, etc.
    An obsessed crank, apparently.

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