[Marxism] human origins

David McDonald dbmcdonald at comcast.net
Thu Aug 11 10:03:42 MDT 2005


Charles Brown:

During the "equilibria", isn't what is being said  that there are changes,
i.e. new characteristics arise, but these characteristics do not amount to
speciating changes?

David McDonald:

As I understand it, the point of Punctuated Equilibrium is exactly that the
Darwinian model of natural selection -- small favorable variations occurring
over long periods suddenly, for various reasons, leading to the emergence of
new species -- is unsubstantiated by the fossil record. Variation is not
recorded in the fossil record as a series of small changes each granting
enhanced reproductive success -- a problem noted by Darwin and explained by
him as due to the extreme episodic nature of the fossil record as known by
humans. Rather, variation seems to be strongest at the emergence of a new
family or genus. It is as if new genera and families have somehow a greater
vigor for variation. The fact that this is unexplained causally is the big
problem that punctuated equilibrium adherents need to solve. What is the
mechanism involved? How do individual organisms "know" they are part of a
new genetic stream and therefore vary more and speciate more rapidly? As a
for instance, one out of ten flowering plant species is an orchid, and
orchids are among the most recent plant families to emerge.

As I have written, the really big fight punctuated equilibrium engenders is
whether evolution operates solely on the individual organism, or whether
higher taxa such as genera evolve as a whole. As I understand the debate
right now, totally as a layperson, punctuated equilibrium is in the
fact-gathering stage. Gould himself was convinced over the decades and
devotes a lot of energy in The Structure of Evolutionary Theory to laying a
stake that his theory preserves the critical essence of Darwinism while
overthrowing what are commonly thought (by professionals such as Dawkins)
essential linchpins of Darwin's theory, like natural selection operating on
individual organisms alone. Gould points out, for instance, that mass
extinction events have had profound impacts on the biota, and that Darwin
never argued that organismal selection ALONE explained the diversity of
life, having, among other things, mentioned "use and disuse," the
cornerstone of the mechanism for evolution advanced by Lamarck, as impacting
evolution.

Others here have praised The Structure of Evolutionary Theory for its
historical approach. It's hard to argue with an historical approach, that's
for sure, but I must say that I find Gould's rambling and discursive telling
of the historical tale way way too loaded with side issues and
irrelevancies. It's nice that he tells us what framework his intellectual
forebearers worked in, but in his desire to present their arguments fairly
and contextually he loses me in the detail, and I am a detail guy when I
need to be. I have found Capital and Theories of Surplus Value tough reads
requiring serious attention but I have never thought they were overloaded
with detail or full of obscure vocabulary. I wish Gould were alive so I
could complain to him personally and demand an Origin of Species-like basic
account of his theory written in non-academese. Ultimately I think TSoET is
self-indulgent and a serious editor ought to have told Gould so. I have the
same problem with Ontogeny and Phylogeny, a perversely unreadable book about
a really interesting question.

David McDonald





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