The more I look into Gould's handling of Darwin in the matter
of distinguishing phyletic gradualism and punctuated equilibria,
the less impressed I get. Gould is fond of saying that Darwin's
meaning cannot be gotten from isolated text-bytes, but rather
from overall tone or some such.
Due to Laurie Appleton's quote of Gould quoting Darwin, I was
induced to have a look at the original. Well, the original
Darwin quote, as well as Gould's. Gould has a text-byte of
Darwin, and I had always assumed before that Gould had gotten
the gist of Darwin's context more-or-less correct. I was a bit
stunned to find that this was *not* the case. Given Gould's
rather abrupt treatment of others who have performed historical
revisionism, I find this more than a little unsettling.
I have previously stated my opinion that Eldredge and Gould
failed to properly credit Darwin with key concepts underlying
PE. Scholars may read the same sources and come to different
conclusions. However, there is a line to be drawn between a
variance of interpretation and what can only stand as either
shoddy scholarship or deliberate misrepresentation.
In a msg on <Aug 08 10:47>, Laurie Appleton of 3:640/238@Fidonet writes:
[Laurie replying to George Rudzinski]
[...]
LA> However, your comment, once again shows that you don't
LA> know much about what Darwin actually said anyway!
Apparently, neither does Gould.
[...]
LA> "The extreme rarity of transitional forms in the
LA> fossil record persist as the trade secret of paleontology.
LA> The evolutionary trees that adorn our textbooks have data
LA> only at the tips and nodes of their branches; the rest
LA> is inference, however reasonable, not the evidence of
LA> fossils. Yet Darwin was so wedded to gradualism that he
LA> wagered his entire theory on a denial of this literal
LA> record:"
LA> "The geological record is extremely imperfect and this
LA> fact will to a large extent explain why we do not find
LA> interminable varieties, connecting together all the
LA> extinct and existing forms of life by the finest
LA> graduated steps. He who rejects these views on the
LA> nature of the geological record, will rightly reject my
LA> whole theory.
LA> "Darwin's argument still persists as the favored escape of
LA> most paleontologists from the embarrassment of a record
LA> that seems to show so little of evolution [DIRECTLY]. In exposing
LA> its cultural and methodological roots, I wish in no way to
LA> impugn the potential validity of gradualism (for all
LA> general views have similar roots). I wish only to point
LA> out that it was never "seen" in the rocks."
LA> "Paleontologists have paid an exorbitant price for Darwin's
LA> argument. We fancy ourselves as the only true students of
LA> life's history, yet to preserve our favored account of
LA> evolution by natural selection we view our data as so bad
LA> that we never see the very process we profess to study."
LA> (Stephen Jay Gould (Professor of Geology and Paleontology,
LA> Harvard University), "Evolution's erratic pace".
LA> Natural History, vol.LXXXVI(5), May 1977, p.14.)
Naughty Laurie omitted one word from Gould, which I have
restored in square brackets.
So what passage, precisely, did Gould identify as indicating
Darwin's intimate stance with gradualism? Here it is...
Note particularly the bits I've highlighted by splitting
out and marking with [!!!].
[Quote]
Summary of the preceding and present Chapters </emph>. I have
attempted to show that the geological record is extremely
imperfect;
[!!!] that only a small portion of the globe has been
geologically explored with care;
that only certain classes of organic beings have been largely
preserved in a fossil state; that the number both of specimens
and of species, preserved in our museums, is absolutely as
nothing compared with the incalculable number of generations
which must have passed away even during a single formation;
that, owing to subsidence being necessary for the accumulation
of fossiliferous deposits thick enough to resist future
degradation, enormous intervals of time have elapsed <pb
n='340'> between the successive formations; that there has
probably been more extinction during the periods of subsidence,
and more variation during the periods of elevation, and during
the latter the record will have been least perfectly kept; that
each single formation has not been continuously deposited; that
the duration of each formation is, perhaps, short compared with
the average duration of specific forms;
[!!!] that migration has played an important part in the first
appearance of new forms in any one area and formation;
that widely ranging species are those which have varied most,
and have oftenest given rise to new species; and
[!!!] that varieties have at first often been local.
All these causes taken conjointly, must have tended to make the
geological record extremely imperfect, and will to a large
extent explain why we do not find interminable varieties,
connecting together all the extinct and existing forms of life
by the finest graduated steps.
<p>He who rejects these views on the nature of the geological
record, will rightly reject my whole theory. [...]
[End quote -- C.R. Darwin, Origin of Species, pp. 340-341]
Within the above quote are key components of *punctuated
equilibria*. The notion that geographical distribution
matters, and that species are at first localized, and then
migrate out are all *critical* features of Eldredge and Gould's
PE. Gould's assertion that the passage shows *only*
consideration of the features of phyletic gradualism is just so
much poppycock. Just so that everyone stays on the same page,
here is Eldredge and Gould's statement of the tenets of
phyletic gradualism:
[Quote]
In this Darwinian perspective, paleontology formulated its
picture for the origin of new taxa. This picture, though rarely
articulated, is familiar to all of us. We refer lo it here as
"phyletic gradualism" and identify the following as its tenets:
(1) New species arise by the transformation of an ancestral
population into its modified descendants.
(2) The transformation is even and slow.
(3) The transformation involves large numbers, usually the
entire ancestral population.
(4) The transformation occurs over all or a large part of the
ancestral species' geographic range.
[End quote]
Note that the passage that Gould extracts his quote from
explicitly violates (3) and (4). (1) and (2) are neither
asserted nor denied by the passage from Darwin. Darwin's
"wedding" to phyletic gradualism appears to have been
unconsummated. At least, the quote which Gould identifies
as showing that relationship clearly instead shows glimpses
of Darwin flirting around with PE. And that is even without
interpreting Darwin's remark about relative durations of
formations and species as indicating an appreciation of the
prevalence of stasis.
Rejection of Darwin's argument amounts to rejection of both PE
and PG. What Eldredge and Gould have done with PE is assert
that certain aspects of Darwin's argument are more important
than other aspects of Darwin's argument. Well, duh. What
takes chutzpah is to then claim that the good bits weren't part
of Darwin's argument all along.
I guess Laurie isn't the only person who can quote out of
context.
Oh, and Laurie should be able to tell us why, if phyletic
gradualism was never seen in the rocks, Gould and Eldredge 1977
specifically validates Ozawa's 1975 paper on forams as showing
a clear example of phyletic gradualism?
--
Wesley R. Elsberry, 6070 Sea Isle, Galveston TX 77554. Information sent to any
of my email addresses is my personal property, to be published as I see fit.
Student in Wildlife & Fisheries Sciences. http://www.rtis.com/nat/user/elsberry
"You raise your eyes\Say that's just like life\There's never quite enough"-BOC
