Wonderful
Life by Stephen J. Gould. Reviewed by
Richard Dawkins in Sunday Telegraph, 25th Feb
1990
If only Stephen Gould could think
as clearly as he writes! This is a beautifully written
and deeply muddled book. To make unputdownable an
intricate, technical account of the anatomies of worms,
and other inconspicuous denizens of a
half-billion-year-old sea, is a literary tour-de-force.
But the theory that Gould wrings out of his fossils is a
sorry mess.
The Burgess Shale, a Canadian rock
formation dating from the Cambrian, the earliest of the
great fossil eras, is a zoological treasury. Freak
conditions preserved whole animals, soft parts and all,
in full 3-D. You can literally dissect your way through a
530-million-year-old animal. C D Walcott, the eminent
palæontologist who discovered the Burgess fossils in
1909, classified them according to the fashion of his
time: he shoehorned them all into modern
groups. Shoehorn is Goulds own
excellent coining. It recalls to me my undergraduate
impatience with a tutor who asked whether the vertebrates
were descended from this invertebrate group or that.
"Cant you see", I almost shouted,
"that our categories are all modern? Back in the
Precambrian, we wouldnt have recognized those
invertebrate groups anyway. You are asking a
non-question." My tutor agreed, and then went right
on tracing modern animals back to other modern groups!
That was shoehorning, and that is
what Walcott did to the Burgess animals. In the 1970s and
80s, a group of Cambridge palæontologists returned to
Walcotts museum specimens (with some newer
collections from the Burgess site), dissected their
3-dimensional structure, and overturned his
classifications. These revisionists, principally Harry
Whittington, Derek Briggs and Simon Conway Morris, are
the heroes of Goulds tale. He milks every ounce of
drama from their rebellion against the shoehorn, and at
times he goes right over the top: "I believe that
Whittingtons reconstruction of Opabinia in
1975 will stand as one of the great documents in the
history of human knowledge."
Whittington and his colleagues
realised that most of their specimens were far less like
modern animals than Walcott had alleged. By the end of
their epic series of monographs they thought nothing of
coining a new phylum for a single specimen
(phylum is the highest unit of zoological
classification; even the vertebrates constitute only a
sub-category of the Phylum Chordata). These brilliant
revisions are almost certainly broadly correct, and they
delight me beyond my undergraduate dreams. What is
irritating is Goulds grandiloquent and
near-disingenuous usage of them. He concludes that the
Burgess fauna was demonstrably more diverse than that of
the entire planet today, he alleges that his conclusion
is deeply shocking to other evolutionists, and he thinks
that he has upset our established view of history. He is
unconvincing on the first count, clearly wrong on the
second two.
In 1958 the palæontologist James
Brough published the following remarkable argument:
evolution must have been qualitatively different in the
earliest geological eras, because then new phyla were
coming into existence; today only new species arise! The
fallacy is glaring: every new phylum has to start as a
new species. Brough was wielding the other end of
Walcotts shoehorn, viewing ancient animals with the
misplaced hindsight of a modern zoologist: animals that
in truth were probably close cousins were dragooned into
separate phyla because they shared key diagnostic
features with their more divergent modern descendants.
Gould too, even if he is not exactly reviving
Broughs claim, is hoist with his own shoehorn.
How should Gould properly back up
his claim that the Burgess fauna is super-diverse? He
should - it would be the work of many years and might
never be made convincing - take his ruler to the animals
themselves, unprejudiced by modern preconceptions about
fundamental body plans and classification.
The true index of how unalike two animals are is how
unalike they actually are! Gould prefers to ask whether
they are members of known phyla. But known phyla are
modern constructions. Relative resemblance to modern
animals is not a sensible way of judging how far Cambrian
animals resemble one another.
The five-eyed, nozzle-toting Opabinia
cannot be assimilated to any textbook phylum. But, since
textbooks are written with modern animals in mind, this
does not mean that Opabinia was, in fact, as
different from its contemporaries as the status
phylum would suggest. Gould makes a token
attempt to counter this criticism, but he is hamstrung by
dyed-in-the-wool essentialism and Platonic ideal forms.
He really seems unable to comprehend that animals are
continuously variable functional machines. It is
as though he sees the great phyla not diverging from
early blood brothers but springing into existence fully
differentiated.
Gould, then, singularly fails to
establish his super-diversity thesis. Even if he were
right, what would this tell us about the nature of
history? Since, for Gould, the Cambrian was peopled
with a greater cast of phyla than now exist, we must be
wonderfully lucky survivors. It could have been our
ancestors who went extinct; instead it was Conway
Morriss weird wonders, Hallucigenia,
Wiwaxia and their friends. We came
that close to not being here.
Gould expects us to be surprised.
Why? The view that he is attacking - that evolution
marches inexorably towards a pinnacle such as man - has
not been believed for 50 years. But his quixotic
strawmandering, his shameless windmill-tilting, seem
almost designed to encourage misunderstanding (not for
the first time: on a previous occasion he went so far as
to write that the neo-Darwinian synthesis was
effectively dead!). The following is typical
of the publicity surrounding Wonderful Life
(incidentally, I suspect that the lead sentence was added
without the knowledge of the credited journalist):
"The human race did not result from the
survival of the fittest, according to the
eminent American professor, Stephen Jay Gould. It was a
happy accident that created Mankind" (Daily
Telegraph, 22nd January 1990). Such twaddle, of
course, is nowhere to be found in Gould, but whether or
not he seeks that kind of publicity he all too frequently
attracts it. Readers regularly gain the impression that
he is saying something far more radical and surprising
than he actually is.
Survival of the fittest
means individual survival, not survival of major
lineages. Any orthodox Darwinian would be entirely happy
with major extinctions being largely a matter of luck.
Admittedly there is a minority of evolutionists who think
that Darwinian selection chooses between higher-level
groupings. They are the only Darwinians likely to be
disconcerted by Goulds contingent
extinction. And who is the most prominent advocate
of higher-level selection today? Youve guessed it.
Hoist again!