This is Carl Woese, he's a biologist. Although I've been aware of several of the theories that he has espoused over the years, it wasn't until recently that I attributed their authorship to this great thinker. Three of the "biggest" ideas that he's responsible for are: the RNA world hypothesis, the current organization of the tree of life with three domains at the bottom, and the concept that there was a time, before species existed, when Darwinian evolution was not dominant because of the prevalence of horizontal gene transfer. Briefly, the RNA world hypothesis suggests that the most primitive version of life as we know it must have consisted entirely of RNA because RNA can act as both an enzyme (for which we mainly use proteins) and as an information storage molecule (for which we use DNA). The three domain system split the prokaryotes (simple cells having little to no internal membrane structure like bacteria) into two separate groups: bacteria & archaea. As to pre-Darwinian evolution and horizontal gene transfer, well the idea there is that before there were individual species, all the forms of life were so similar that there was massive intermixing of genetic information betwen living organisms such as we do with bits of electronic data today. This is incredible because it's essentially akin to lizards appropriating wings from birds because they're an effective way to avoid ground predators (excuse the hyperbole).
This is Gertrude (gerry) Brin and her grandson Colby, another great thinker. In reading Colby's blog post from today, about his grandmother and life in general, I was reminded of what I think is Woese's most powerful idea.
As an undergraduate student of Physics and Mathematics just starting to become interested in Neuroscience, and delighted by the fact that I could use my beloved equations to explain the behavior of biological systems, it none the less seemed to me that we would need an entirely new form of Mathematics, spurred by a paradigmatic shift in thinking, to really understand such complex systems as brains and indeed life in general. The best that I could do was to think of life as a temporary reduction in entropy. Perhaps you remember from some physics course that the universe is constantly tending towards an increasing state of disorder (entropy). This is true on a global (all-universe) scale, but smaller scale things such as life defy this. Life forms, temporarily, organize molecules. I've never been able to do much more with this idea, but I am fond of it and try to consider its ramifications once in a while.
One of the big problems we've had with understanding these very complex systems, is that all of our science has been reductionist for a very long time. We take something we don't understand (a watch is one classic though not ideal example) and we open it up and look at all the pieces and how they fit and work together, and then we can understand in some way how the watch functions, but only in terms of the smaller pieces. I could say much much more about this, but I think Dr. Woese says it far better in the piece he wrote in Microbiology and Molecular Biology Reviews in 2004. I must also preface the following quote from that work by saying that I was turned on to ALL of this by Freeman Dyson's fantastic article in the July 19th issue of the New York Review of Books (that link may expire fairly soon, I found it by googling the second paragraph of the text below), which also uses a substantial portion of the quote that follows.
"Let’s stop looking at the organism purely as a molecular machine. The machine metaphor certainly provides insights, but these come at the price of overlooking much of what biology is. Machines are not made of parts that continually turn over, renew. The organism is. Machines are stable and accurate because they are designed and built to be so. The stability of an organism lies in resilience, the homeostatic capacity to reestablish itself. While a machine is a mere collection of parts, some sort of “sense of the whole” inheres in the organism, a quality that becomes particularly apparent in phenomena such as regeneration in amphibians and certain invertebrates and in the homeorhesis exhibited by developing embryos.
If they are not machines, then what are organisms? A metaphor far more to my liking is this. Imagine a child playing in a woodland stream, poking a stick into an eddy in the flowing current, thereby disrupting it. But the eddy quickly reforms. The child disperses it again. Again it reforms, and the fascinating game goes on. There you have it! Organisms are resilient patterns in a turbulent flow—patterns in an energy flow. A simple flow metaphor, of course, fails to capture much of what the organism is. None of our representations of organism capture it in its entirety. But the flow metaphor does begin to show us the organism’s (and biology’s) essence. And it is becoming increasingly clear that to understand living systems in any deep sense, we must come to see them not materialistically, as machines, but as (stable) complex, dynamic organization."
That last sentence just kills me, we must in some sense abandon our devotion to the material. For what is life about if not interaction.
5 comments:
LOVE the flow analogy, and yet i still cant help but feel that it is composed of individual parts itself (and i know im nitpicking, and that's not your general point, but im gonna continue with my general pt...)
the child himself, composed of his many molecules, the stick itself, composed of its woody goodness, the stream, its watery whathaveyou - as a human being, with my human brain, i still cant get past dissecting it all into parts, a la the watch. i understand the desire to look at the organism as more than a molecular machine (great term, btw), but my question is HOW?
im no scientist, but it seems like we reach a pt where we have to just throw our hands up and say 'we dont know how the hell this all goes on!' like, we can get asymptotically closer and closer, but my intuition tells me we'll never get there. hence, my idea it's magic/god.
i feel like you scientists, in this respect, are truly on a quixotic journey. but dont get me wrong - i think it's more than necessary, and admirable. like i said in my post, it's kind of the essential question.
so bottom line - mr. met - do you think we'll EVER unlock the magic (as i do not), or do you think we'll get closer and closer, but never pin it down? are our brains even capable of pinning it down?
do my questions belie my ignorance?
have i used belie correctly? is it bely?
anyway, great post.
mantis force!
in other words, WHAT is allowing for all this renewal? like you said, physics, as we understand it (them? it's plural?!) tells us that really only entropy is possible. so how the hell is this renewing going on?
in this house we abide the laws of thermodynamics!
btw, and this is my LAST comment on this post, i forgot that youve actually met toto.
my grandparents were at that h.s. graduation party my mom had. i like the fact that you met her b/c i think one of the other pillars of life is that we all pass this ball of magnetism between each other, simply by being in each other's company. so you've passed that ball around with toto yourself, even if it was a mere introduction.
I love the post!
The quote from Dr. Woese inspired me to reread the section "The Need for Criteria by Which to Recognize Thinking" in Douglas Hofstadter's "Fluid Concepts and Creative Analogies." Although the quote is about cognition and not the behavior of all biological systems, I think it is appropriate:
"We recognize human kindness by observing kind acts, not by doing DNA-testing to see if a person has an underlying "kindness gene" or by doing a real-time brain scan to see if some kind of "empathy center" is actually engaged. We recognize a word processor by what it does on a screen in response to keyboard input, not by what hardware it runs on. We have behavioral criteria for kindness in humans. It would not be too hard to set up some behavioral criteria for recognizing word-processing programs. Turing, in his famous article, attempted to suggest a similar set of criteria for recognizing thinking entities.
"In analogy to such criteria for recognizing kind acts or word processors, Turing's idea is to employ a set of high-level behavioral criteria as opposed to low-level implementational criteria. Turing did not make the dogmatic presumption that, simply because brains are made out of neurons, the only possible level of description of any system that could think is the level of neurons. Instead, he built on what people intuitively mean when they refer to thinking -- namely, the fluid manipulation of ideas. Turing does not a priori tie such manipulation to any kind of hardware; he remains open as to what the proper level of description of the mechanisms responsible will turn out to be.
"When all the results of mind/brain research are finally in, will the best way to talk about "the human brain" wind up being in terms of standard types of neural wiring patterns? Or standard types of neural clusters? Or standard types of interrelationships of neural clusters? Perhaps the details of neurons themselves will not matter. Conceivably, in fact, even the internal structure of neural clusters will not matter anymore than do organic chemistry and quantum mechanics. In such a case, the underpinnings of thinking would be revealed to lie pretty distant from biology and much closer to abstract organizational principals -- which is to say, software. Who knows -- it might even turn out that the proper "brain structures” required for the fluid manipulation of ideas are roughly at the level of the mechanisms of Copycat, Tabletop, and Letter Spirit, or a little bit lower."
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