Wednesday, December 19, 2012

Roger White on Origin of Life Explanations 2



Roger White distinguishes three types of phenomena, illustrated by “pebble patterns.” 
The Chancy Explanation: Pebbles scattered randomly on a sidewalk require no other explanation than chance. 
Unintentional Biasing: Pebbles arranged in order of diminishing size as they a near the shoreline. 
Intentional Biasing: Pebbles arranged in the shape of a fish (without legs). 
I altered the last one in a way that I hope will be amusing.  According to White, all but a few of those who write with expertise on the problem of the origin of life believe this phenomenon must fall into the second category.  Some natural forces must bias the Kosmos toward the emergence of life, just as the tides bias the pebbles toward a coherent pattern. 
The third explanation is ruled out as unscientific.  The first is ruled out because it is wildly implausible that the conditions upon which the emergence of self-replicators depends should have come about, in the time allotted, merely by chance.  Unintentional biasing must therefore be true by default. 
White argues that the reason that the origin of life is not at all like the unintentional biasing of pebbles by size on the beach. 
The numerous steps required for life to exist are quite unlike this. It is not a matter of the same event-type or property being instantiated many times without exception. The conditions required for the emergence of life have little at all in common.
Adding a bit to what White says, the emergence of life on earth seems to have been a single event (however long it took), not a repeated pattern. 
Why then are most scientists so reluctant to allow too much chance into their accounts of life’s emergence? I will offer a speculative diagnosis. The conviction that life couldn’t have arisen by chance is typically a gut reaction to the data, not a conclusion arrived at on the basis of a theory about when it is plausible to ascribe something to the work of chance.
What makes this event seem so implausible to so many is that it seems to suggest unmistakable evidence of design. 
Again adding to White, I would contrast the origin of life problem with the problem that Darwin addressed.  Why do so many different organisms exist, all of them more or less well adapted to their respective ecological niches?  That is a pattern that is persistent historically and geographically.  Natural selection then can be seen as the unintentional biasing mechanism analogous to the motion of water acting on the pebbles. 
Interestingly, unintentional biasing would be a much more likely explanation for the origin of self-replicators if Aristotle had been right about spontaneous generation.  If the emergence of living organisms from non-living matter under predictable conditions were a persistent feature of nature, as Aristotle, for understandable reasons, believed that it was, then unintentional biasing toward the emergence of life would be very likely indeed.  Of course, this is not the case. 
White makes a strong case that unintentional biasing in nature is not a well-grounded explanation for the origin of life.  That leaves chance and intentional (or intelligent) design.  I would suggest, however, that his dismissal of the gut reactions of so many scientists is premature.  To use one of his analogies, if a tornado picked up a pile of spare parts and assembled it into a working 747 airliner, no one would interpret this was the work of mere chance.  If even the simplest molecular self-replicators as well-designed as the airplane (which may be the case) and unintentional biasing is not a plausible interpretation of the former, then…
I am not making an argument for intelligent design here.  I am not particularly interested in it only because I don’t know what to do with it when thinking philosophically and scientifically about the phenomenon of life.  I do think that White’s argument could be turned almost as easily (perhaps just as easily) into an argument for intelligent design as for the origin of life by chance.  That fact may tell us something about the phenomenon.  If so, it would be unscientific to ignore it.  

4 comments:

  1. I found this discussion fascinating, but I am having some difficulty understanding what "unintentional biasing" is, unless it's just another form of chance.

    You describe it as "Pebbles arranged in order of diminishing size as they a near the shoreline." Ok - that makes sense - but why are they arranged that way? Isn't it either because of chance or design?

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  2. MF: the constant action of the waves pushes the pebbles uphill, towards the shore line. The smallest pebbles get pushed the farthest, which is why the beach is full of sand. Larger pebbles tend to end up away from the shoreline, in rough proportion to size.

    Thus there is a bias in the action of waves toward a certain arrangement of pebbles. If you were to mix the pebbles up in a perfectly random assortment of sizes and then allow the waves to work, the arrangement described above would reappear.

    Likewise, if you consider the arrangement of male guppies in pools going up a mountain. The males go from almost camouflaged in the lowest pools to very brightly colored in the highest pools.

    Two forces of selection are at work: sex selection and predator avoidance. In the lower pools there are many predators. Males that stand out much don't survive long enough to mate. In the upper pools where there are fewer predators, brightly color males can survive to mate, and the brighter they are the more visible and attractive they are to females.

    A scientist named Endler remixed the assortment of guppies and placed them in five tanks with similar sand and plants. In each tank there were similar numbers of dull and brightly colored males. Then he placed predators in each tank to reflect their populations in the pools. Tank 1, many predators, Tank 2, fewer, etc. In a short time the situation in the wild reasserted itself. Dull males in Tank 1; flamboyant males in tank five. That is unintentional biasing.

    It is different from chance because chance will produce a variety of arrangements each time and depends heavily on the original state. Unintentional biasing will produce the same pattern every time regardless of the original state.

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  3. Thank you for taking the time to explain. I understand your distinction a bit better now, but I think I agree with White's idea that unintentional biasing doesn't work the same way something like a pebble arrangement does. While certain factors such as the movement of the waves might explain something like the arrangement of the pebbles, eventually, if you ask "how and why" enough, assuming you can always get to the bottom of those answers, there eventually has to be something that happened before everything else did. And if nothing else had happened yet, you wouldn't have anything like the constant action of the waves to attribute its happening to. Eventually, unless I'm missing something big (which is quite possible!) it's got to boil down to chance or design.

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  4. M.F.: I think you interpreting chance to mean precisely "not-designed". That is a very important distinction, but there is still a difference between "unintentional biasing" and chance.

    If we find a stone formation that looks a little bit like a bear because of the way that wind and water have carved it, that is chance. The fact that a real live grizzly bear looks like a bear is not chance. Its mother and father were bears.

    Darwin explains how you get designed things by means of unintentional biasing. As to why the Kosmos produced a planet on which life emerged, it is conceivable that there is some force acting from the beginning of K, analogous to natural selection, that pushed K in that direction. White, I gather, thinks that such an explanation for life is weak.

    It is conceivable that the conditions for life and its emergence were mere matters of chance, like the rock that looks like a bear. Apparently, the scholarly consensus is that that is untenable.

    Having distinguished between chance and unintentional biasing, we can now say that if White and the consensus are both right, then intentional biasing is the only viable explanation. We report. You decide.

    The question as to what came before that is the famous cosmological question. Is it conceivable that K has always existed just as it is (with all the biasing laws) and that the only explanation is that it just is? Or do we require a creator-God who Himself just is? Big question.

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