----- Original Message ----- From: "Chuck Grimes" <cgrimes at rawbw.com> To: <lbo-talk at lists.panix.com> Sent: Monday, June 24, 2002 10:09 PM Subject: Gould
>
>
> Finally got started on Gould's `The Structure of Evolutionary
> Theory'. Below is a long excerpt that I think probably
summarizes the
> entire thrust of the book. Pretty awesome stuff. On the other
hand, I
> have no idea how this will strike biologists. Any other there
want to
> comment?
>
> Chuck Grimes
> --------------
>
> ``As the most striking general contrast that might be
illuminated by
> reference to the different Zeitgeists of Darwin's time and our
own,
> modern revisions for each essential postulate of Darwinian logic
> substituted mechanics based on interaction for Darwin's single
locus
> of causality and directional flow of effects. Thus, for Darwin's
near
> exclusivity of organismic selection, we now propose a
hierarchical
> theory with selection acting simultaneously on a rising set of
levels,
> each characterized by distinctive, but equally well-defined
Darwinian
> individuals within a genealogical hierarchy of gene,
cell-lineage,
> organism, deme, species, and clade. The results of evolution
then
> emerge from complex, but eminently knowable, interactions among
these
> potent levels, and do not simply flow out and up from a unique
casual
> locus of organismal selection.
========================
The notion of multiple scales and loci of selection on planet Earth has been around for a while. What I've always found puzzling about biology and the ontological issues it inquires about is the fascination, especially with male biologists, is hierarchy. Especially when it's damned difficult to determine if the hierarchies are artifacts of our theories or they are really "out there." The numerous turf wars over reductionism and which niche of researchers was really onto *the* driver of evolutionary change always seemed to me to be more about us than the phenomena under investigation.
> A similar substitution of interaction for directional flow then
> pervades the second branch of selection's efficacy, as Darwin's
> fundamentalist formulation---with unidirectional flow from an
external
> environment to an isotropic organic substrate that supplies
`random'
> raw material but imposes no directional vector of its own to
`push
> back' from internal sources of constraint---yields to a truly
> interactive theory of balance between the functionalist
Darwinian
> `outside' of natural selection generated by environmental
pressures,
> and a formalist `inside' of strong, interesting and positive
> constraints generated by specific past histories and timeless
> structural principles. Finally, on the third and last branch of
> selection's range, the single and controlling micro-evolutionary
locus
> of Darwinian causality yields to a multileveled model of tiers
of
> time, with a unified set of processes working in distinctive and
> characteristic ways at each scale, from allelic substitution in
> observable years to catastrophic decimation of global biotas.
Thus,
> and in summary, for the unifocal and non-interactive Darwinian
models
> of exclusively organismal inside, and a microevolution-ary locus
for
> mechanisms of change that smoothly extrapolate to all scales, we
> substitute a hierarchical selectionist theory of numerous
interacting
> levels, a balanced and bidirectional flow of casuality between
> external selection and internal constraint (interaction of
> functionalist and structuralist perspectives), and causal
interaction
> among tiers of time.
==============
Why not think in terms of webs rather than hierarchies or both webs and hierarchies with neither accorded greater epistemic privileging? Time would be very interested to know that humans in the 21st century thought of "it" in terms of tiers rather than arrows. :-)
> Among the many consequences of these interactionist
reformulations,
> punctuational rather than continuationist models of change (with
> stronger structuralist components inevitably buttressing the
> punctuational versions) may emerge as the most prominent and
most
> interesting. The Darwinian mechanics of functionalism yield an
> expectation of continuously improving local adaptation, with
longterm
> stability representing the achievement of an optimum. But
> interactionist and multi-leveled models of causality competing
forces
> at numerous levels, with change then regarded as exceptional
rather
> than intrinsically ticking most of the time, and punctuational
rather
> than smoothly continuous when it does occur (representing the
> relatively quick transition that often accompanies a rebalancing
of
> forces).
==================
How many times does the word complementarity show up in the index compared to competition?
>
> To end this admittedly vague section with the punch of paradox
(and
> even with a soundbite), I would simply note the almost delicious
irony
> that the formulation of a hierarchical theory of selection---the
> central concept of this book, and invoking a non-vernacular
meaning of
> hierarchy in the purely structural sense of rising levels of
> inclusivity---engenders, as its most important consequence, the
> destruction of a different and more familiar meaning of
hierarchy:
> that is, the hierarchy of relative value and importance embodied
in
> Darwin's privilaging of organismic selection as the ultimate
source of
> evolutionary change at all scales. Thus, a structural and
descriptive
> hierarchy of equally effective casual levels undermines a more
> conventional hierarchy of relative importance rooted in Darwin's
> exclusive emphasis on the micro-evolutionary mechanics of
organismal
> selection. And so, this structuralist view of nature's order
enriches
> the structure of evolutionary theory---carrying the difference
between
> strict Darwinism and our current understanding through more than
> enough metatheoretical space to fashion a Falconerian, not
merely a
> Darwinian, rebuilding and extension for our edifice of coherent
> explanation.'' (32-3p)
====================
What's a "rising level of inclusivity"? Who/What's "Falconerian"
Ian