PZ Myers. 2005 Sep 25. Puzzling over theory. <http://pharyngula.org/index/weblog/puzzling_over_theory/>. Accessed 2008 Sep 06.
Posted on M00o93H7pQ09L8X1t49cHY01Z5j4TT91fGfr on Sunday, September 25, 2005
Puzzling over theory
On Saturday, I gave a talk to the Minnesota Atheists on a bit of the evidence for evolutionary history. In one part of the talk, I gave an analogy for what biologists do, and I thought I'd expand on it a little bit here.
A theory is a powerful thing, a tool for interpreting observations and experiments, and the way to assess the utility of a theory is to examine how well it explains the available facts, whether it suggests new experiments and leads to new insights, and whether it contradicts any of the evidence. What we do with a theory like evolution is use it to interpret and assemble what we see into a coherent whole. The process is like assembling a jigsaw puzzle.
This, for instance, would be a single datum; an observation, like the discovery of a fossil hominid, or an experiment, such as a genetic perturbation of a Hox gene. It's the building block of our work. On a day to day basis, what scientists do is gather these little pieces of the puzzle; to a point, this can be done without any reference to a unifying theory. In isolation, they are often cryptic and esoteric, and honestly, the lay public has reason to be baffled about why we poke around with such odd things. Certain creationists of limited imagination, like Phil Skell, try to argue that the fact that a scientist can run a gel or dig up a bone without giving evolution a thought means that evolution is superfluous.
Think about what you do with a single puzzle piece, though: the next step is to go looking for a second piece, one that fits with it. In a typical jigsaw puzzle, you make inferences that you test. For instance, you may assume that it's a landscape, so blue pieces will be part of the sky, green pieces might be part of the trees or grass, etc., and we test those hypotheses by searching for pieces that correspond in color or texture to our first. The final test, of course, is to see whether two pieces actually fit together.
We repeat this process over and over. After a fair amount of progress, you usually have a general idea of what you're putting together. The way everything fits together, the general rules we see working (such as pieces that fit together well, and that we see sensible patterns emerging as assembly progresses) represent the theory. If none of the pieces fit, we'd have to announce that our theory of the jigsaw-puzzleness of the pieces was false. If there was no similarity in the texture or color of adjacent pieces, we say the theory of landscapeness was false. If we get to the point where our puzzle looks like this…
…we'd feel very comfortable with the idea that these assorted strangely shaped pieces of cardboard were part of a puzzle, and that once they are put together we'll have a photograph of some part of the world. It's nowhere near complete, but the big picture is coming into focus nicely. We keep plugging away at it, and we continue to make progress, so the theory is satisfying and unchallenged.
Of course, this analogy isn't perfect. We'd need a much more complicated puzzle, one that my daughter would balk at putting together, and it would also have to be unbounded. Evolution is one of the biggest, most complex puzzles humanity has ever faced.
Where do creationists come into this story? They're kibitzers. They're the annoying people who stand around and claim that there's no way this puzzle can be finished. Who reach in and pluck out random pieces and try to hammer them together. Who ignore the completed work and point to the gaps and tell you what goes there (and it has nothing at all to do with the developing theme of the image). They are unproductive nuisances.
Intelligent Design creationists are particularly aggravating. They pick up isolated pieces and declare that it doesn't fit anywhere in the puzzle—that it is anomalous and doesn't relate to any other piece. The scientist's response, of course, is to snatch it back and rummage around and find another piece with which it interlocks, but that doesn't stop the IDist. He just picks up another piece and repeats his assertion. They don't bother to explain where they think their purportedly anomalous piece belongs, either…it's enough that they declare without cause that it doesn't belong.
Without the theory to tie disparate pieces together, this is all we have:
That's biology without the theory of evolution: the facts are all there, but they are fractured and disorganized. We reject that, not just because it is esthetically unsatisfactory, but because it requires that we consciously neglect unambiguous connections—it demands a willful blindness. That's a trait common in creationists, but it is the antithesis of scientific thinking, where insight and the ability to find connections are valued.
(Thanks to Skatje for the puzzle construction!)
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Good analogy.
Paul Nelson would be the guy on the side, saying, "Those pieces only fit together by coincidence."#: Posted by on 09/25 at 07:43 PM -
On Sunday, there was a letter in the New York Times from Ahren Sadoff, Professor of Physics at Cornell University.
I wrote to him in reply:
You (Dr Sadoff) wrote:
"The crucial criterion for any scientific theory is that it must make testable predictions (not "post"-dictions). Would the proponents of intelligent design please tell us what are the testable predictions of their "theory"?"
Congratulations on getting a letter published in the NYT!
I've been trying without sucess for many years.
There is no one "theory of evolution".
Evolution is a process. Living things change over time. The organisms of the present and the adaptations, structures and processes that they display have changed over time. They are different from the past. Evolution is as much a fact as "the sky is blue".
On the other hand, neo-darwinism (the "modern synthesis"), the notion that evolution is the accumulation of random, accidental mutations filtered by natural selection, is a mechanism. While mutations do occur, and natural selection is a real phenomenon that no thinking person questions, what is absent is any kind of nexus linking the trivial effects of mutation and natural selection to the emergence of highly organized structures, processes, adaptations and systems.
I am not a religious creationist, and I have no religious agenda. I have been an agnostic my whole life. I am a scientist with advanced degrees and years of experience teaching science and supporting the scientific method. Intelligent design is a perfectly plausible mechanism for evolution and falls nicely within the domain of legitimate science. Unfortunately, it's consideration has been hijacked by religious creationists to promote their own religious agenda.
As Feynman said: ""God was invented to explain mystery. God is always invented to explain those things that you do not understand. Now, when you finally discover how something works, you get some laws which you're taking away from God; you don't need him anymore".
I'm confident that at some time in the future we will discover how evolution works and that this explanation will move the discussion squarely into the realm of science.
All one has to do is examine the various systems, structures (try molecular motors) and processes that make up functional, living organisms and one would be hard pressed to explain these phenomena using nothing more than random, accidental, unguided events as claimed by evolutionists (darwinists in particular). That there is an intelligent input involved appears to me to be self-evident.
Now I'm not claiming the existence of God. Only an intelligence higher than human or some as yet to be discovered "first principle". But one does not have to identify this entity before one accepts the inadequacy of the darwinian paradigm.
My position is simple: Accept evolution as a process and reject darwinism as a mechanism.
The "modern synthesis" is slowly being superceeded by new understandings in embryology and genetics sometimes referred to as "evo-devo". Just as development of an organism is guided by a computer algorithm in the genome, so evolution most likely is the unfolding of a similar computer algorithm that functions on a population level, rather than the organism level. What we refer to as "evolution" is most likely the unfolding of this program that was already present at the time that the first life forms arrived on earth from elsewhere. And most likely, just as a mature organism has run it's program to it's conclusion after its development is complete, so the evolutionary algorithm has most likely also run it's course and what we see today is primarily extinction and diversity within existing groups.
http://www.charliewagner.com
http://enigma.charliewagner.com
http://www.charliewagner.com/casefor.htm
Charles Wagner
Lahaina, HI 96767
#: Posted by charlie wagner on 09/25 at 08:01 PM -
A slightly different emphasis on the jigsaw puzzle analogy may also be useful: You don't need all the pieces fitted together to see what the picture is. A similar analogy might be a brick wall. Even if some of the bricks are missing, when enough of them are in place it becomes unmistakably recognizable as a wall.
#: Posted by on 09/25 at 08:03 PM
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ahhh. but the fast that the pieces fit together to form a picture just means that they were intelligently designed!
(humor here!)#: Posted by on 09/25 at 08:30 PM -
Another good way to continue the analogy would be to say that some pieces of the puzzle are lost and will likely never be found. Thus, the puzzle will never be absolutely complete, but as well, fitting together pieces around any gaps requires an even greater understanding of the puzzle as a whole and where the connections are. Where we have a missing piece, we can still continue around it, because we can extrapolate from the pieces that we do have.
#: Posted by on 09/25 at 08:36 PM
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Heh-heh! I guess William Dembski would be the guy who claims the pieces were created by some sort of intelligent designer. He'll tell one group of people that he'll have a theory any day now which will explain how the pieces must have been intelligently designed, and another that he knows God created the pieces and that assembling them represents a mockery of the Almighty.
#: Posted by on 09/25 at 08:40 PM
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Yeah, but I'll betcha Dembski never shows you the jigsaw the designer cut the pieces out on. That's not part of his version of science -- none of that mechanistic stuff for him.
RBH#: Posted by on 09/25 at 08:58 PM - Hey, this is very similar to the way to use the jigsaw puzzle to teach scientific method - something that you described here a few months back and I successfully integrated in the classroom several times since then. Great to have NEW pointers for this (including from the commenters).
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And here's a delightful little new puzzle piece:
http://www.world-science.net/exclusives/050923_tinydinofrm.htm -
I wish I could have been there as it sounds like an excellent talk. Maybe next year. As an aside, I've always thought Sagan's little parable of "The Westminster Project" in "The Demon-Haunted World" makes a similar point, albeit indirectly. The story is intended to highlight the value of pure research but it also emphasises the power of a successful theory as something that works. Take away Maxwell's equations and you probably take away much of the technology we take for granted today: radio, TV, radar, phones, etc.
#: Posted by on 09/26 at 02:06 AM
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Thanks for the link, coturnix - way cool!
#: Posted by on 09/26 at 04:26 AM
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Dembski would be the one telling you there's no indication of who the puzzle designer was, all the while hoping you won't notice the big box on the floor saying "PRODUCT OF MILTON BRADLEY GAMES".
#: Posted by on 09/26 at 06:38 AM
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accumulation of random, accidental mutations filtered by natural selection
one would be hard pressed to explain these phenomena using nothing more than random, accidental, unguided events
So, five bucks says Charlie will never comprehend at what point his logic derails here... Here is a hint: If I blind fold myself, wander around the yard dropping random piles of dirt, then when done drop a hose and let water run through it, the water will still follow the path that physics demands, guided by all the random piles of dirt I dropped. By the same token, **if** such piles end up flat, or humped up, depends also entirely on physical laws, like if the ground is uneven or there are holes in it. The @%@#%$!# entire world, including all those other randomly mutating species 'guides' evolution, none of it is random. If it was, then we would see species of animals in caves that have 'never' been exposed to light randomly developing fully functional eyes and things living above ground, where that thing, you know, big bright yellow ball..., makes having them useful, who never develop them at all. We don't. Anymore than land animals have a need to randomly develop fin, or gills, elephants need wings, birds need armor plating or ID people need logic.
Its not unguided. Its not not guided by some rediculous super intelligence, that you can't come up with **any** better explaination for or test to prove than the hypothesis itself. - That should have been 'just not' in the last sentence.
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Please tell me your "theory" in four sentences or
less. There is one caveat. You are not allowed to use
negative definitions, i.e.
"What is a cat?"
" A cat is not a dog."
The utter shamelessness of these ID proponents is
fully summed up in William Demski's response to a
negative review of his book "No Free Lunch" by H.Allen
Orr. Notice the statement in parentheses mid way
through the second paragraph.
..."(just when or how is a matter for further
study)"...
http://www.bostonreview.net/BR27.5/exchange.html
When I first read this, I had to stand up and walk
around for ten minutes, I was so gobsmacked!! These
people want us to teach as a counterweight to the most
tested theory in science, "I don't know how it works,
or when it happened, or who did it,or in what order,
but it is".
Belay the endless refutations of misqoutes,the
pointing to obvious errors of terms, the obfuscations
and outright lies. Simply stand back and ask them for
the lesson plan to teach this subject. And once again,
no negatives. "ID is right because evolution is
wrong."
Sincerely, P.C.Chapman#: Posted by on 09/26 at 03:41 PM -
Charlie Wagner is a nitwit who is notorious for claiming on Panda's Thumb that human beings might have designed all the life on earth (yes, including themselves).
Ignore him.#: Posted by on 09/26 at 05:10 PM - Aha! Just listened to the Lou Dobbs Show on CNN in which there was a debate between an ID'er and an advocate of teaching real science in the classroom (unfortunately it just aired and I didn't get the names or affiliations of the participants). What was remarkable was that when it was argued that ID was just an attempt to get religion into the classroom by the back door, the ID'er did not demur but shot back that the teaching of evolution was a means to get the teaching of atheism in through the front door. This short debate further exposed the ID'ers for exactly whom they are - religious no-nothings who want to return to the "halcyon" days of the inquisition.
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crackpot charlie is back!
He keeps insisting that he is "a scientist with advanced degrees and years of experience teaching science and supporting the scientific method."
Which of course is immediately refuted by one (among his usual) crackpot assertion that "Intelligent design is a perfectly plausible mechanism for evolution and falls nicely within the domain of legitimate science."
He is not consciously aware that he just cited the reason why it is not: "The crucial criterion for any scientific theory is that it must make testable predictions (not "post"-dictions). Would the proponents of intelligent design please tell us what are the testable predictions of their "theory"?"
He thinks evolution is explained by "using nothing more than random, accidental, unguided events as claimed by evolutionists (darwinists in particular). That there is an intelligent input involved appears to me to be self-evident."
That the theory (theories) of evolution is based both on random variation (sex, mutation) and _nonrandom_ natural selection (culling) is still outside charlies comprehension.
I can not take Kagehis wager since it is obvious charlie will never get it.#: Posted by on 09/26 at 05:37 PM -
GWW, yes perhaps we should ignore him.
I once saw him claim that, in effect, the universe may have eternal history with no big bang. Which is another major crackpot theory nowadays.
I do not think it is nitwit, he should be able to check on facts easily enough. It is just addledbrain thinking, which may never touch reality however we argue the facts. So your statement is more apropos than my argument.#: Posted by on 09/26 at 05:52 PM -
The puzzle was my favorite part of the talk.
Thanks for the big post on it, PZ. -
I once saw him claim that, in effect, the universe may have eternal history with no big bang. Which is another major crackpot theory nowadays.
Aw, come on...
The Colliding Branes Theory (however sophomoric) absolutely kicks Intelligent Design's ass!
#: Posted by on 09/26 at 10:30 PM -
Great post.
and... I think I have Charlie figured out. He cannot conceptualize time. All of that complexity from a random event... Impossible!
Hundreds of millions of years, trillions of generations... Shifting continents, glacial recession... it does not compute.
What does he do? He makes stuff up! Stuff that fits in the available real estate. Stuff that gives him that cozy feeling that he really understands. Data? We don't need no stinkin' data! This makes sense to me! I feel GREAT!
Ahh...#: Posted by on 09/27 at 09:49 PM -
"The Colliding Branes Theory (however sophomoric) absolutely kicks Intelligent Design's ass!"
The WMAP data on background radiation shows that the universe has an age (which is compatible with the age of all observed cosmic objects) and that the universe started with the big bang and inflation. http://map.gsfc.nasa.gov/m_mm.html
Whatever caused (in the sense of explaining) the big bang we have currently no observations of.
But I agree that these creation theories kick creationist theories ass. Since they predict stuff, they matter.
#: Posted by on 09/28 at 01:29 PM -
While this is a good analogy of how scientific inquiry works, it struck me as a pretty dangerous way of presenting the evolution/ID-controversy, as a jigsaw puzzle quite obviously has a designer (gotta be careful with the analogies).
#: Posted by on 09/29 at 06:53 AM
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I've used the puzzle analogy...but more like the comparison version, some here have already suggested. If you have two pictures one of, shall we say, Darwin to represent evolution, and another of Michelangelo's image of God giving life to Adam from the Sistine Chapel and you have a puzzle in front of you that is only half done...could you tell which picture it will look like when/if it was finished? What if you only had 25% of the pieces? Some of the pieces may be lost forever, but you should still be able to tell the difference between the two. If you want to try to suggest that it's the painting by Michelangelo, you have to reconcile all of the existing puzzle pieces(facts) that are in front of you.
#: Posted by on 09/29 at 11:23 AM