[ From Rick Marken (921208.1200)
Bill Powers (921204.1430) --
But I am still bothered by the idea of the environment, the stupid
environment, selecting anything.
penni sibun (921207.1600) replies --
because the environment is *not* ``non-living.''
Maybe Bill should have said "anything external to the organism" instead
of "environment". I believe the point was that PCT would encourage
biologists to look inside the individual organism for the processes that
do what turn out to be the evolutionary selecting -- and not read too
much into the apparent selecting performed by events outside of the
organism. There could be an illusion here -- similar to the illusion that
consequences (reinforcements) control behavior. But maybe not. In the
reinforcement case the loop is clearly closed -- actions influence
consequences (reinforcements) and consequences influence
actions. And when there is a closed loop (and the sense of the feed back is
negative) you have control -- in this case, control of perception of rein-
forcement. Things are not so clear in evolution; actions (phenotypes)
certainly do influence consequences (eg. survival capability) but
it is not clear that consequences influence actions (phenotypes). One way
that the latter might happen has been ruled out be research -- inheritance
of acquired characteristics. (It could have been that successful actions
(phenotypes) got coded back into the genes so that the phenotypes of the
next generation would produce better consequences (survival capability).
But this doesn't happen). Another alternative (not, as far as
I know, seriously considered until recently) is that consequences (survival
capability) influence actions (phenotypes) by influencing the probability
of a mutation -- mutation becomes more probable when the organism
is experiencing itself as surviving poorly. There was some research that
suggested that such a link from action to phenotype (via mutation
probability) might actually exist -- (the study was reported in Nature)
but it is still controversial and not generally accepted. I have also heard
of evidence that the probability of cancer (the result of a mutation) is
greater when people are "stressed" -- ie. experiencing poor survival
capability. So there is some (weak) evidence that "how you are doing"
(actions) can influence the probability of a mutation. If this actualy
happened (and I'm prepared to believe that it doesn't, even though I
would like to believe that it does) it would add an "active" controlling
dimension to evolution (like my e. coli model) -- one that goes beyond the
currently accepted mechanism -- "Darwin's Hammer" -- which is based
on the idea that there is no (direct) feedback connection from consequence
(survival ability) to phenotype. This still may be the right idea, but, as
Bill P.
said, it seems rather inefficient. "Darwin's Hammer" is unquestionably part
of the evolutionary story -- but not necessarily a big part or, even, the
most important part. But we won't know until biologists start to do the
right kind of research.
Best regards
Rick