Serial Endosymbiosis and Intelligent Design
AUTHOR: Allen MacNeill
SOURCE: Original essay
COMMENTARY: That's up to you...
It's very gratifying to see Lynn Margulis finally getting the recognition that she deserves. As the most effective exponent of the serial endosymbiosis theory (SET) for the origin of eukaryotes, Lynn's work provides an excellent example of how ID should (but currently doesn't) proceed. During the late 1960s, Lynn published a series of revolutionary papers on the evolution of eukaryotic cells, culminating in her landmark book Symbiosis and Cell Evolution, in which she carefully laid out the empirical evidence supporting the theory that mitochondria, choloroplasts, and undulapodia (eukaryotic cilia and flagella) were once free living bacteria (purple sulfur bacteria, cyanobacteria, and spirochaetes, respectively).
Her theory was greeted with contempt and scorn by almost all evolutionary biologists (sound familiar?), who believed at the time that all eukaryotic cellular organelles evolved by gradual elaboration of invaginations of the plasma membrane. But Lynn didn't give up, or continue to simply restate her original theory (sound familiar?). Instead, she continued to do extensive field and laboratory research, publishing hundreds of papers and dozens of books in which she presented the accumulating empirical evidence supporting her theory. With time, other researchers (encouraged by the success of her field and lab research) began to test her hypotheses themselves, and discovered yet more empirical evidence supporting her theory.
And so today, Lynn Margulis's SET has become the dominant theory explaining not only the origin of eukaryotes, but also the origin of evolutionary novelty at dozens of different levels in biology (see her book, Acquiring Genomes for a comprehensive review). So well accepted has her work become by evolutionary biologists that finally, after almost four decades, creationists and ID supporters have begun to attack her theories. As she said at our Darwin Day celebration at Cornell this past February, no greater affirmation of one's "having arrived" as a major theorist in evolutionary biology could be imagined.
The point here is that, if ID wants to become accepted as part of evolutionary biology in the same way that Lynn Margulis's SET has become accepted, then ID supporters have to do the same thing she did: get out in the field and get your hands dirty, and get into the lab and do the same thing. Her ideas were just as unorthodox and unacceptable in 1969 as ID is now. However, she didn't put all of her effort into public relations and political propaganda. No "Symbiosis Institute" dumped millions into the production of deliberately distorted press kits and one-sided propaganda films. Legions of self-appointed experts whose only exposure to biology was in high school classes or what they read on Answers in Genesis or Uncommon Descent bloviated on SET and declared themselves experts after a week of superficial study of articles on Wikipedia.
No, Lynn and her colleagues did the hard work of finding the empirical evidence that eventually carried the day and established her SET as one of the bedrock foundations now worthy enough of respect as to earn the ire of the creationists and IDers. Her ideas are still radical, and still raise the blood pressure of many evolutionary biologists. Her dismissal of the "modern evolutionary synthesis" in particular is not popular among many evolutionary biologists, who are largely still mired in paradigms that are at least four decades of out of date. She has said some things about the "modern synthesis" that have brought smiles to the faces of the creationist quote-miners. The difference between her and them is that they can't even begin to claim any credibility in science; their "work" is entirely parasitic on hers, and deserves nothing but contempt.
When the history of evolutionary biology in the 20th century is written (I hope to contribute to it myself, if I live long enough), the work of Lynn Margulis will rank right up there with the work of Fisher, Haldane, Wright, Dobzhansky, Mayr, Simpson, Stebbins, Gould, Lewontin, Kimura, Williams, Hamilton, Trivers, and the two Wilsons. And unless and until IDers decide that it's finally time to stop doing agitprop and start doing science, they and the creationists will at best be a trivial footnote.
Comments, criticisms, and suggestions are warmly welcomed!
--Allen
Labels: evolution, evolutionary phylogeny, Ford Doolittle, intelligent design, Lynn Margulis, macroevolution, serial endosymbiosis, tree of life
posted by Allen MacNeill @ 4/27/2008 11:08:00 AM
12 comments
12 Comments:
Margulis deserves full credit for recognizing that mitochondria and chloroplasts are derived from bacteria via endosymbiosis.
Many of her other ideas have, quite rightly, been rejected by the scientific community.
No "Symbiosis Institute" dumped millions into the production of deliberately distorted press kits and one-sided propaganda films.
Tsk, tsk. Are you hoping we have forgotten about the Symbionese Liberation Army? ;)
Yes, congratulations to Margulis for working hard to get here endosymbiosis ideas incorporated into the mainstream.
However, she seems to now be overstating the impact of this idea. During her Darwin Day talk at godless Cornell, she claimed that "genome acquisition" is responsible for _all_ speciation. Well, we now have complete genomes for humans and chimps, who diverged roughly 6 million years ago. It should be a simple matter to point out the evidence of recent genome acquisition that contributed to the speciation episodes involved.
Margulis may be getting too comfortable playing the maverick. She has also made comments which reveal her to be an HIV/AIDS denialist.
So we must continue to evaluate each bright idea by how well it is supported by evidence.
As Larry Moran said, Margulis is an important contributor to her field. However, she did not originate the endosymbiosis hypothesis: much like plate tectonics, the idea had been around for decades before her. Her work, and her stubbornness, led to its establishment as the best explanation for the origin of eukaryotes -- and for that she is certainly to be admired. At the same time, her sole original contribution to SET was the idea that undulipodia had a symbiotic origin: one that she continues to champion in spite of its having been soundly refuted. To argue against her assertion that mutation is an insignificant source of genetic diversity is hardly to subscribe to "be mired in paradigms that are at least four decades of out of date." She does indeed enjoy playing the maverick, and does so to a fault. Likewise, she denies that anthropogenic global warming is a problem, and denies that HIV causes AIDS. These are not respectable positions in modern science, and for very good reason. She is unquestionably a great figure in science, but that does not make everything that she says or does right.
I think it's important to understand what Margulis is getting at before dismissing her more recent ideas. In particular, when she mentions "genome acquisition", she is speaking in a more general context than the mechanisms that gave us chloroplasts and mitochondria. Specifically, she is referring the growing appreciation that organisms (individually and perhaps at higher levels of organization) are collections of genomes - the "main one" as well as many other symbionts, mutualists, parasites, and the like. Her idea is that speciation, evolution, and the like are not solely matters of changes in the "main" genome, but also of changes in the range of associated genomes.
Whether she's correct or not is an open question. But the idea isn't so far-fetched as one might imagine. And it will be fun testing it.
I don't think that Lynn calls them "neodarwinian bullies" because she thinks that her theoretical extensions get a similarly fair evalutation of the evidence. Neodarwinians know that Lynn's ideas about symbiogenesis and self-regulating systems lead to her and Lovelock's Gaia Hypothesis and its teleological implications for a predetermined purpose.
Dawkins and others have very vocally insisted that hell will have to freeze straight over before anyone in the community accepts anything that looks that much like "god" to them, and I don't believe that any amount of evidence is going to get a fair evaluation if it results in an admission that there is evidence that we're not here by accident.
I commented for a while on Uncommon Decent until I realized that they had absolutely no desire to actually do any real research. All they do is blog, read (and criticize) other's research, and try to convince the public that they're real science.
One thing I've realized is that there IS no theory of Intelligent Design. If you talk to someone that agrees with Intelligent Design, you don't know if they believe in a young-earth or old-earth, common descent or not, if evolution happens at all or not. And if you even mention the word God, they throw a hissy fit and say "Well you're first mistake is that you assume that the designer is God." even though pretty much everyone there believes it is.
They just want to stay in this fuzzy area in the fringe of a coherent idea so that they don't make any assertions whatsoever. If you try to infer testable predictions from their stance, they'll take an even less tangible and falsifiable idea as their stance. It's nothing resembling science.
Neodarwinians know that Lynn's ideas about symbiogenesis and self-regulating systems lead to her and Lovelock's Gaia Hypothesis and its teleological implications for a predetermined purpose.
That would have been an argument, if a Gaia hypothesis leads to teleology instead of feedback. The same goes for the presumption that certain researchers rejects teleology because of its implications. The truth is that there have never been observed processes that displays teleology, so it would be a hard sell.
And the comment looks as if the posts message was rejected out of hand; do the obligatory extensive field and laboratory research and show us empirical evidence supporting a teleological process, before contempt and scorn is to be removed.
The Russian biologist A. I. Operin wrote a small book (in Russian) in 1936, that was translated and published in 1953 entitled “Origin of Life.” In chapter VIII of his book, “Further Evolution of Primary Organisms,” he discussed the work of B. Kozo-Poljanski, “Outline of a Theory of Symbiogenesis” (1924), and B. Keller, “Botany on a Physiological Basis” (1933), both in Russian. Both of these scientists presented what would later be called “endosymbiosis.”
Kozo-Poljanski advanced the idea that the eukaryotic cell was the product of the “symbiosis of simplest living organisms.” Keller is quoted as, “… We are developing the view that at some distant time in its history the cellular nucleus (nucleated cell?) passed through a stage when it existed as a colony of elementary living units similar to the colony stage through which the multicellular organism passed. Bacteriophages and genes are the remnants of those living units.” Operin then noted that, “It is possible and, perhaps probable that the cell nucleus did originate from such primary living units not directly but through an intermediate stage of more complex living things, like the bacteria.”
Again from Keller (1933), “Chlorophyll grains (chloroplasts) also must have been at one time independent living units, simpler than the cell itself, but containing the green substance, chlorophyll. … This symbiosis of organisms, which was at first accidental, gradually became elaborated into a most intimate and permanent system in which the previously independent organisms acquired the character of organs of a single whole, the cell.
(Translations by Sergius Morgulis 1938)
Having been lucky enough to be a student in two courses taught by Dr. Margulis at the University of Massachusetts - Amherst, I can only wonder at the lack of recognition of her work by the Nobel Prize committee.An oversight I sincerely hope they remedy in her lifetime.
C.Stubbington
Cathrine, I think that Stanley Miller ought to have receoved a nobel. However, they are occasionally obsessed with exaggerated ideas of "originality."
In Margulis's case, she was conceptually anticipated by three scientists by over 40 years. She had the first empirical results, but in this case theory trumped experiment for "credit."
I am a mostly data driven guy, and it always made me angry that "theoreticians" could get drunk and make up any BS they liked, and then claim all the credit if they guessed correctly. When they were lame-ass jerks (most of the time), they just wandered off into some new content free speculation. However, an experimentalist actually had to do some real work, and when they found evidence that was significant, a jackass theoretician will have claimed the credit. Since there are three "theoreticians" on four sides of any two-sided question, a real worker will never be credited for their work.
Gary Hurd (google has screwed up again)
Much as I have enjoyed what Margulis has written, the thing the really knocked my socks off was Donald Williamson's "The Origin of Larvae."
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