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From: wcalvin@milton.u.washington.edu (William Calvin)
Newsgroups: comp.ai.philosophy
Subject: Re: emergence
Message-ID: <8724@milton.u.washington.edu>
Date: 7 Oct 90 19:56:39 GMT
References: <1990Oct4.173933.7319@ux1.cso.uiuc.edu> <6@tdatirv.UUCP> <8712@milton.u.washington.edu>
Organization: University of Washington, Seattle
Lines: 135

Emergent properties include all sorts of nonbiological examples,
such as the pattern of linked back eddies downstream from a
rapid; there is a list of the ones seen from a float trip through
the bottom of the Grand Canyon at Mile 166 in my 1987 book on
brains and evolution, _The River That Flows Uphill_ (Sierra Club
Books).
     One of the more interesting emergents is anatomy:  patterns
of development that produce patterns of body parts.  It has
always been hard to imagine quite how a designerless system
gradually shapes up anatomy towards some unwritten-in-the-genes
optimum.  But form tends to follow function for some interesting
reasons that began to be recognized in the aftermath of Darwin. 
I thought that, in the spirit of Minsky's postings a few years
ago from his book, that I would excerpt two pages from Chapter 2
of my forthcoming (12/90 from Bantam in hardcover) book,
The Ascent of Mind
Ice Age Climates and the Evolution of Intelligence.

-----------------------------------------------------------------
                 copyright 1990 by W. H. Calvin
GENES NEED ONLY be approximately correct, as a little behavioral
versatility can do the rest.  While this versatility during life
may not alter the genes passed on to offspring, it does serve to
shape up those genes:  behavior can drag along anatomy.  This was
recognized by three scientists in 1894; though often called the
Baldwin Effect, it probably ought to be called the Morgan-
Baldwin-Osborn Effect.  Perhaps we would understand it more
intuitively were it called the Old-Family-Recipe Effect.
     Anyone who has ever asked for a copy of "that wonderful
recipe" knows that the recipe card is always faded, flour-
encrusted, written in a style of handwriting favored by some
first-grade teacher of long ago, and smeared by several ancient
droplets of an unknown fluid.  And so when you transcribe it onto
a new card to carry home with you, some copying errors are
likely.
     What's worse, the donor of this recipe has long since
stopped consulting the recipe card:  she just bakes from memory
and, over the years, has improved the cake (or whatever)
considerably beyond what would result from faithfully following
her written recipe.  Indeed, she has no idea how much her
"handful of flour" departs from the half-cup that the recipe
calls for, or how inaccurate the temperature setting on her oven
has become.  Still, she has found the winning combination (you
did, after all, ask for the recipe) and so her point-of-departure
version of the recipe comes to be copied with an unintentional
mutation or two.
     This commonplace situation suggests a simplified scheme for
how cake-baking contests at county fairs could "cause" better
cakes to evolve.  Pretend for a moment that success in baking
cakes obeys the following rules:

1.  Each participant inherits a randomly altered copy of her
     "parent's" recipe for a cake.  Perhaps a teaspoon of baking
     soda is changed into a tablespoon's worth.  Or the 385
     baking temperature into 335.  Or some other such alteration
     in the mix of ingredients, amounts, times, and temperatures.

2.  The cook can modify the recipe during her lifetime, but only
     by memory, not by amending the recipe card.  Indeed, since
     the recipe card is merely the point of departure for
     experimentation, it need never be consulted again (until
     finally copied).

3.  There are contests to select the better cakes, and the
     winners and runner-ups are the ones most likely to have
     offspring attracted by the cake-baking contests in some
     future decade.  Note that winners don't train offspring at
     cooking (in this simplified scheme):  they only pass on
     their point-of-departure version of the recipe.  The only
     thing that experience, i.e., the recognition of good
     variations, does in the long run is to make the winners'
     offspring more likely to become contest-minded cake bakers.

4.  The judging doesn't change criteria over the years ("good
     taste is eternal").  

The recipe's mutations are usually worse than the original.  In
any generation, of course, an off-on-the-wrong-foot cook who is,
nonetheless, skillful at fiddling the recipe may hit upon the
combination that constitutes the optimal recipe; inheritance is
not fate (but she cannot pass on this winning combination as
such, just the degraded recipe card).  Yet on the average, the
copying errors that move away from the optimal make it less
likely that unwritten variations in the recipe ("a lifetime of
experience") will hit on the optimum.
     Because losers tend not to have offspring that participate
in such contests (the losers don't get asked for a copy of their
recipe), diverging recipes are more likely to die out.  And so
there will be a slow convergence in copying errors toward the
optimal combination, just by carving away the other combinations. 
The optimal recipe may never be written down, but the population
of written recipes in use gets closer and closer to the
combination of ingredients, amounts, times, temperatures, and
assembly procedures that will satisfy the expert tasters of
cakes.
     Allowing a son or daughter to learn the parent's hard-earned
variations on the recipe would represent Lamarckism:  inheritance
of acquired-during-life characteristics.  This "Training Effect,"
of course, happens with real cooks and their offspring; we
encourage this mode of transmission with schools and books.  But
we theorists may temporarily leave such influences out of
explanations, just to demonstrate that the whole population of
written recipes (or whatever) can nonetheless shift closer and
closer to the unwritten optimal even without the additional
Lamarckism (in the case of biological inheritance, we also leave
instruction out because there is little evidence for it).
     Adding some version of Lamarckian shaping has two
interesting effects:  cakes converge on the optimal even more
quickly, but the written recipes converge more slowly than they
would otherwise.  (In the terminology of evolutionary biology: 
With Lamarckism, the phenotypes evolve faster but, paradoxically,
the genotypes evolve slower!)  Should there be a "lost
generation" that never learns to cook from their expert parents,
the grandchildren will have to start over from instruction cards
that haven't been shaped up anywhere as far as they might
otherwise have been.  While shaping up the "written version" may
be safer in the long run, one has to first survive the short run
-- and climates often shift so rapidly that survival depends on
changing food-finding strategies just as quickly (in the cake
analogy, suppose that next year's judges went sour on sugar, all
trying to lose weight because of a new preventive medicine
campaign against obesity).  And so both the Old-Family-Recipe
Effect and the Training Effect may prove essential in the short
run because the judging criteria have changed.
     In the analogy, the individual ingredients-and-procedures
are the genes, the recipe is the sperm-or-ovum, and the whole
population of cake recipes is the genome.  And, of course, the
cake is only the recipe's way of getting a copy made of itself. 
The Selfish Recipe has struck again.
                               ###

                    William H. Calvin
                    University of Washington -- Biology NJ-15
                    Seattle WA 98195       ph. 1-206-328-1192
                    wcalvin@u.washington.edu