Re: History and Goals (for TE)

Craig Rusbult (rusbult@vms2.macc.wisc.edu)
Sat, 20 Jun 1998 12:32:08 -0500

An important question for TE -- "How reproducible is unguided
evolutionary history: If the history was allowed to "run freely with uMIO"
numerous times, would the outcomes be widely divergent or strikingly
similar? -- is answered very differently by Stephen Gould and by Daniel
Dennett.

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Gould discusses history throughout "Wonderful Life", and "history" is in
the titles for the last two chapters (4 & 5).

on pages 320-321 is a summary of Gould's view: "The divine tape recorder
holds a million scenarios, each perfectly sensible. Little quirks at the
outset, occurring for no particular reason, unleash cascades of
consequences that make a particular feature seem inevitable in retrospect.
But the slightest early nudge contacts a different groove, and history
veers into another plausible channel, diverging continually from its
original pathway. The end results are so different, the initial
perturbation so apparently trivial."

also, for example,
page 314: "If Ediacara had won the replay, then I doubt that animal life
would ever have gained much complexity, or attained anything close to
self-consciousness."
page 318: "We must assume that consciousness would not have evolved on
our planet if a cosmic catastrophe had not claimed the dinosaurs as
victims. In an entirely literal sense, we owe our existence, as large and
reasoning animals, to our lucky stars." (referring to the dino-killing
comet)
page 320: "...biology's most profound insight into human nature, status,
and potential lies in the simple phrase, the embodiment of contingency:
Homo Sapiens is an entity, not a tendency."
page 323, the book's final sentence concludes that "We are the offspring
of history, and must establish our own paths in this most diverse and
interesting of conceivable universes -- one indifferent to our suffering,
and therefore offering us maximal freedom to thrive, or to fail, in our own
chosen way."

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Although Dennett expresses a similar "indifferent universe" worldview in
"Darwin's Dangerous Idea," he adopts a very different view of contingency.

on page 308, a summary: "There aren't *global* pathways of progress, but
there is incessant *local* improvement. This improvement seeks out the
best designs with such great reliability that it can often be predicted by
adaptationist reasoning. Replay the tape a thousand times, and the Good
Tricks will be found again and again, by one lineage or another.
Convergent evolution is not evidence of global progress, but it is
overwhelmingly good evidence of the power of processes of natural
selection."

pages 304-306: "he [Gould], looking at these amazing creatures, can't
imagine why some would be better designed than others. ... That is not good
evidence that they didn't in fact differ dramatically in engineering
quality, given their respective predicaments." / But it doesn't matter
much because "even if the decimations of the Burgess Shale fauna were
random, whatever lineages happened to survive would, according to standard
neo-Darwinian theory, proceed to grope towards the Good Tricks in Design
Space" and "the result will be hard to tell from the winner that would have
been there if some different lineage had carried on."
page 306: "When you do rerun the tape of life, you find all sorts of
evidence of repetition. We already knew that, of course, because
convergent evolution is nature's own way of replaying the tape." / Gould
does not deny convergence -- how could he -- but he does tend to ignore
it." / "Just what is Gould's claim about contingency? ... There is a
sliding scale on which Gould neglects to locate his claim about rewinding
the tape." [Dennett then describes expectations for historical
reproducibility that would be too specific or too general, and concludes
that Gould is claiming something intermediate, which (according to Dennett)
can be achieved by evolution.]

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back to Gould, page 289: "A final point about predictability versus
contingency: Am I really arguing that nothing about life's history could be
predicted, or might follow directly from general laws of nature? Of course
not; the question that we face is one of scale, or level of focus. ...
Invariant laws of nature impact the general forms and functions of
organisms; they set the channels in which organic design must evolve. But
the channels are so broad relative to the details that fascinate us! ...
When we set our focus upon the level of detail that regulates most common
questions about the history of life, contingency dominates and the
predicatbility of general form recedes to an irrelevant background."

A QUESTION: If Gould thinks "the details that fascinate us" are
controlled by contingency, a theistic evolutionist should be even more
concerned about whether "the details that fascinate God" are controlled by
contingency. Or are "the goals of God" so broad that contingencies
(whether on the level envisioned by Gould or Dennett) don't produce a
significant effect?

Craig