Re: Pattern of PE

Wesley R. Elsberry (
Mon, 8 Mar 1999 12:23:14 -0600 (CST)

David J. Tyler wrote:
>On Fri, 5 Mar 1999, Wesley R. Elsberry wrote:

WRE> Can Neal list any significant part of the pattern of PE that
WRE> Darwin did not mention in his first edition of Origin of Species?

DJT>I just happen to be reading something relevant to this.
DJT>The better question is: "Is PE something Darwin antipated,
DJT>or is it revolutionary for Darwinism?"

Is it a better question? Neal's claim had to do with the
"pattern of PE" and when it was recognized. This question of
David's seems to be pretty much irrelevant to Neal's claim,
so I fail to see *how* it happens to be a better question in
the context of this discussion. It certainly is an interesting
question in its own right, though. My view is that Darwin can
be credited with recognizing the pattern of PE, but not with a
complete explication of a mechanism to explain that pattern.
But Darwin did give several biological reasons for fossil
record completeness, a fact disregarded by many scholars.

Here's a quote by a couple of those authors....

DJT>"But, despite the rhetoric, the theory [PE] was
DJT>revolutionary for two reasons. First, it took the fossil
DJT>record at face value for the first time since Darwin, who
DJT>had invoked gaps in the record to explain away the absence
DJT>of intermediate forms in evolutionary lineages. Large
DJT>gaps certainly exist but can commonly be overcome by
DJT>replicate sampling in different places. Second,
DJT>morphological stasis was unexpected, despite revisionism
DJT>to the contrary." Jackson, J.B.C. and Cheetham, A.H.
DJT>1999. Tempo and mode of speciation in the sea. Trends in
DJT>Ecology & Evolution, 14(2), 72-77.

DJT>For the record, this is a quote that I agree with.

Darwin gave both geological and biological reasons for
incompleteness of the fossil record, a fact Jackson and
Cheetham overlook. It certainly can be argued that those who
followed Darwin overlooked stasis, but it is difficult to pin
a lack of appreciation of stasis on Darwin himself.

I'd like to give Neal some more time to respond to the
original query before going into more detail on these issues.