Richard Dawkins,
Darwin’s latterday
pit-bull, has a missing link.
Or, rather, had. With the publication
of his tenth book, The
Greatest Show on Earth, Dawkins
finally gets around to filling a conspicuous
void in an evolutionary
oeuvre that spans nearly forty
years. As Dawkins himself explains,
all his previous books primarily
deal with the power of natural
selection and simply assume that
evolution has happened. Dawkins
outlines the goal for his latest tome
in the introduction:
Evolution is a fact, and this
book will demonstrate it.No
reputable scientist disputes
it, and no unbiased reader
will close the book doubting
it.
That ostentatious declaration sets
the bar high, but by the final flowery
chapter, after over 400 pages of
dramatic evidence, it is apparent
that the author has successfully
cleared the hurdle.
The book’s September 2009
release was just in time for the
sesquicentennial anniversary of
the publication of Charles
Darwin’s On the Origin of Species,
certainly no mere coincidence. In
fact, Dawkins’s book shares many
conspicuous parallels with
Darwin’s first edition from 1859.
Both have 14 chapters (including
Dawkins’s appendix) and follow
much the same outline for "one
long argument" intended to establish
the scientific case for evolution.
Both begin by setting out the
evidence for natural selection, first
treating artificial selection in the
origin of domesticated animals and
plants and then moving to bona
fide natural selection in the wild.
Like Darwin, Dawkins next proceeds
methodically to the ample
evidence from the fossil record,
from developmental biology, from
biogeography, and finally from vestiges
and other remnants of historical
contingency. But Dawkins’s job
is much easier than Darwin’s was,
and it is correspondingly more
compelling. Here in the 21st century,
the evidence for evolution is
indeed great, much more diverse
and extensive than 150 years ago
when Darwin wrote the Origin.
Chapter after substantial chapter,
we are treated to the many
independent, converging lines of
evidence that all point to the same
conclusion: the fact that "all living
things are cousins". Dawkins
devotes an entire chapter to geological
dating, covering radioactive
methods, tree rings, geological strata,
and leading fossils, with a clear
refutation of the oft-made charge
that fossil dating is circular.
Dawkins really finds his stride in
the fifth chapter, "Before our very
eyes". Here Dawkins discusses several
cases of evolution observed in
real-time in both the lab and the
wild, including the impressive
Lenski experiments on twenty years
of controlled bacterial evolution.
By the sixth chapter (on transitional
fossils) one gets the feeling
that Dawkins is really batting them
out of the park, and he keeps on
hitting homers for the rest of the
book. Dawkins covers topics often
given short shrift in other books of
this kind, and his treatment of the
modern molecular evidence, ranging
from protein folding to molecular
phylogenetics, is particularly
satisfying. His consideration of the
molecular clock and the neutral
theory of evolution is especially
useful and avoids some of the
more common misconceptions
that have persisted even in the primary
literature.
I was singularly pleased to see
David Penny’s formal test of common
descent brought to a larger
audience, where five independent
protein phylogenies are shown to
display statistically significant similarities
— a result expected if the
species harboring these proteins
are genetically related. In the closing
chapter, Dawkins deconstructs
line by line, as if explicating a
poem, the famous final paragraph
of Darwin’s Origin. This unorthodox
conclusion is perhaps the
finest chapter of the book, touching
on the universal genetic code,
abiogenesis, thermodynamics, the
RNA world, and the anthropic
principle.
Stylistically, this latest offering
harbors no surprises, and if you
have enjoyed Dawkins’s previous
books, you will not be disappointed
with this one. Dawkins is the
prince of scientific analogies and is
uniquely adept at conveying difficult
and complex scientific concepts
by extracting otherwise
arcane similarities from more familiar
things. The embryonic development
of an animal is likened to
"inflating origami". Protein folding
is compared to the spontaneous
bunching of magnetic beads on a
beaded necklace. If, over the millennia,
you could hear the ticking
of neutral fixations in the molecular
clock, it would sound, according
to Dawkins, like the random crackling
of a Geiger counter.
Dawkins’s frustration with creationists
and the excesses of religion
are plainly sensed in this
book, as in his others, and his indelicate
remarks, though largely justified,
will undoubtedly be offputting
for many potential readers:
The history-deniers
[Dawkins’s euphemism for
anti-evolution creationists]
themselves are among those
that I am trying to reach in
this book. But, perhaps more
importantly, I aspire to arm
those who are not historydeniers
but know some ...
and find themselves inadequately
prepared to argue the
case.
Flaws and quirks aside, Dawkins’s
message will quite likely hit its
intended target, as well as open
some of the more hardened minds
of evolutionary skeptics.
In a book on evolutionary evidence,
it is hard to avoid a few nods
towards debunking the common
creationist fallacies. Nevertheless,
unlike many other popular books
that cover the evidence for evolution,
this is not primarily a refutation
of creationism or "intelligent
design" arguments. Rather,
Dawkins’s latest book is a positive
commemoration of the triumph of
a grand arching theory that has
withstood the continuous
onslaught of 150 years of new data,
including the tsunami of molecular,
genetic, and sequence data from
the past fifteen years.
In the final analysis, The
Greatest Show on Earth will take a
deserved place alongside other
"must-read" evolution books. No
other book currently available
approaches Dawkins’s comprehensive
yet accessible treatment of the
extraordinarily diverse and massive
body of data that drives ineluctably
to the same conclusion, the only
conclusion that makes sense of
everything in biology: that all the
"endless forms" of known life share
a common genetic kinship, as they
have been, and are being, evolved.