Myxobacter & Emergence

The example of the “myxobacter” species of bacteria was used in a presentation I saw a couple of years ago at David Gurteen’s 3rd Knowledge Management Conference, at which David Snowden’s management of complexity was a main theme. [Blogged earlier]. I couldn’t be sure who’s presentation it was and I was unable to track down the original slides, so I did a bit of web research myself. Someone over on MoQ-Discuss wanted a real life example of “emergence” …. this is what I posted a few days ago …

Is it a bacterium, is it a worm, is it a mushroom ?

In an earlier thread when I was trying to explain emergence, I made a passing reference to a particular bacterial lifecycle that produces some very strange emergent effects from many “atomic” individuals, that look very much a higher form of purposeful life. Those bacteria are a group called Myxobacter, and there are several different species that all exhibit variations on this lifecycle.

(1) As bacteria, their normal single-celled life is to sit around in their nutrient medium and multiply individually (vegetatively) by cell division. Drop a few specimens on an agar Petri-dish, and they grow into a spreading slimy mass on the surface. Situation normal.

(2) When they hit limits to nutrients (ie they “sense” starvation) “they” do some funny things collectively.

(3) They start to “collaborate” – they start to “move” in blobs en-mass – sometimes the motion is wavelike – like a flat caterpillar – sometimes sliding like a slimy worm or slug – as if looking to find more nutrients.

(4) If they continue to starve, they (collectively) try a different strategy. They stop travelling and form fruiting bodies and lift them up on stalks – like a mushroom made of zillions of collaborating individuals – they individually start to specialize in their roles in the collective whole. When ready, the fruiting bodies burst and release spore-like individuals into the environment.

(5) Some lucky individuals land somewhere moist and nutritious, and the cycle starts over again from (1)

The question that seems to raise itself is … Clearly the single celled-bacteria are already alive in our biological sense, but as individuals have have no complex structures like brains, nervous systems, or even primitive limbs for locomoton, such as we might find in higher order living things.

Is that purposeful quest for nutrition, and the strategies for moving and dispersing to find it, inherent in each individual, or is it emergent from the complex arrangement and interaction of the collection ?

As one commenter pointed out that behaviour is very close to that of the developing human zygote, rather than that of single-celled individuals.

13 thoughts on “Myxobacter & Emergence”

  1. Perhaps you can help me understnd this better…By emergent do you mean that the capacity doesn’t exist before the neccessity is “felt”. Can anything emerge if it is not inherent? But then the next question would be how does the capacity become inherent?

    The answer to that, I guess, is natural selection wherby the individual possessed of a certain trait will either reproduce and reproduce that trait or not.

    But I think the question you are addressing is more about the collabortive effort and how that affects the process.

    Please advise, a biologist I am not.

  2. Forget the biology for a minute … your general knowledge is more than good enough. This is about emergence as a matter of principle.

    In some sense the behaviour of the collective bacteria must “be inherent” in the individuals’ DNA – they have no other means of communicating generation to generation … other than drowning in the same chemical soup as most of their offspring, a soup that their presence must influence …. which is key.

    The point of emergence is that there is nothing in the individuals that would enable you to predict (with any direct causality) the behaviours of the collective – except maybe patterns of common cell structures and DNA sequences etc – which might alert you to expect myxobacter-type behaviour when compared to other myxobacter you already know, but not specific predictable behaviour.

    As Arlo has pointed out of MoQ-Discuss, it’s the combination of top-down (collective to individual) influence and “communication” as well as (and at the same time as) the more obvious bottom-up “causality” that produces the emergent patterns of behaviour in the whole. Hofstadter is right about recursive systems and loopy behaviour.

    You can predict from a human arm and elbow design that an individual might be able to throw a rock, but not that a collection of them might be going to play a symphony … not sure that’s a directly relevant metaphor.

  3. So at some level emergence has to do with the ablility to predict, guess, hypothesize….which doesn’t prove emergence, but rather proves that we have limitations on what we are able to predict.

    The “unpredictable” element of course is all the myriad influences the individual will encounter, otherwise known as life.

  4. Well, yes, but since so much of argumentation “proving” anything uses logic and (implicit) causation ….

    (If this, then that, so therefore when, etc .. the then’s and therefore’s imply some causal connections between the this’s and that’s)

    … emergence explains why that can’t really work (beyond simple repeatable cases) … logical positivism is useless … it’s not about unpredictability in any uncertain statistical sense.

    Even if you knew the position and state of every individual myxobacter in a mass, and knew every physical or chemical effect that linked them, you could not predict the progress of the mass – not without seeking the emergent layers first and talking about these as the objects involved with the processes.

    The corollary of this, and the reason for my interest, is that in fact all “objects” we talk about are really this ephemeral, something emergent (patterns of activity) in underlying layers of interactions. The “conventional” objects make it possible to talk in terms of cause and effect, but whatwever causation really is, it’s pretty weird … dependent arising, to use the buddhist analogy.

    99% of everyday life uses logic and causation to decide and justify … and it’s 99% wrong … I find that worrying. (Don’t quote me on the 99’s)

    Emergence explains why we have such enormous limitations on predictability (causation), and what to look for if you’d like an answer better than the fatalist “oh well, that’s life” 😉

  5. “what to look for if you’d like an answer better than the fatalist “oh well, that’s life”

    Hey, I’m not a fatalist…I’m a femme fatale.

    Yeah, I’d like a better answer, or should I say, a better informed opinion. And we get that every day. It’s sifting through the bullshit that takes time and effort, but I’ve never been one to say “Oh well” just “that’s life”

  6. I’ve been interested in the myxobacter ever since, in the early 1970s, bright yellow slime mold began creeping across my dark green back yard in Ft. Lauderdale. I suspect the fact that the emergence of this behavior/capability is not predictable reflects the level of our scientific observation.

    Hey, Alice — I know of Edward de Bono, AND I wanted to get in touch with you. Please email me if you see this.

  7. Be interested to know what you meant by “level of observation” Georganna ?

    It’s corrcet in the sense that looking at the “atomic” level … the individual bacteria … you can predict nothing about the mass.

    You need to look at structures / patterns in the mass before you get anything like causal predictability … which is kinda the point on this behaviour being an example of “emergence”

  8. I was thinking more about our understanding at the genetic level. Obviously this behavior does not arise from “magic” but from an implicit ability we cannot yet detect. It is probably a complex mix of physical and chemical properties. We already know it occurs in response to environmental factors — stimulii for which there must be receptors and perhaps a rudimentary computational system. I agree about structures/patterns.

  9. But again Georganna,

    It’s not some lack of knowledge or uncertainty (though there is no doubt plenty of it) at the sub-cellular level that is the reason you cannot “predict” even bacteria from genetic / DNA, without first understanding emergent life patterns at a higher level.

    The causality is not all “bottom-up”.

    Those stimulations and responses do not involve the DNA or genes at all, and the bacteria themselves only through the bacterial mass itself.

  10. BTW on De-Bono …

    I did link to him quite recently here …
    http://www.psybertron.org/?p=1290

    It’s not so much that I’m “ignorant” of him, more that it’s 10 or 15 years since I was aware of him, and I’d “moved on”.

    I’d be interested in what you see as specifically relevant to my agenda here.

    Ian

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