 Darwin:
Discovering the Tree of Life
Niles Eldredge, W W Norton & Company, 2006.
Pp 288. ISBN 0-393-05966-9.
In 1966, an American graduate student was supervising my live-trapping
of rats in a grain warehouse in Calcutta. A few years my senior, he
was doing field work for his doctorate in ecology from a leading American
research university. We recorded the numbers of fleas on each rat as
part of a study of the transmission of plague. Some rats had far more
fleas, and other rats had far fewer, than would have been expected from
a random (Poisson) distribution of fleas. I began speculating to the
graduate student that this over-dispersed frequency distribution had
evolutionary implications. In that cramped, hot room stacked high with
bags of grain, he said to me: “You know, I don't think I could ever
believe in evolution.” Uncharacteristically—because I was stunned speechless,
not because of any great self-control—I kept my mouth shut. I learned
then, and have never forgotten, that evolution's roots on my home continent
may have penetrated the topsoil but have not yet breached the bedrock.
Only in 1987, in Edwards v Arkansas, did the US Supreme Court proscribe
the teaching of creation science in all American public schools.
40 years too late for my Calcutta adventure, the exhibition Darwin
would have been my best response to the mental fog in the minds of that
then-young man and the 57% of today's Americans who, according to a
public opinion poll, say they believe in, or lean toward, creationism.
This exhibition and the accompanying book by the curator Niles Eldredge
could not be more timely or more needed.
The exhibition approaches the facts and the theory of evolution by
natural selection from a historical perspective. It starts with ideas
of species and views of evolution that preceded Charles Darwin, and
then focuses on Darwin's life and work—his privileged family background,
his unpromising boyhood and youth (he dropped out of medical school),
his total addiction to natural history, botany, and geology at Cambridge
University, his 5 years on HMS Beagle, and the rest of his long, extraordinarily
productive, and richly recognised life and career.
The exhibition documents and illustrates what Darwin saw on the Beagle
and how his observations raised doubts about the constancy of species
and the adequacy of biblical time scales to account for major changes
in evolution. The viewer learns how Darwin transformed these observations
and doubts into a triumphant theory of a mechanism of biological evolution.
Darwin's theory is triumphant because it has been corroborated by direct
observations of evolution in laboratories, hospitals, and agricultural
fields around the world (notwithstanding his erroneous genetics and
his omissions of punctuated equilibrium and lateral or horizontal transfers
of gene fragments, genes, and genomes). Only Darwin's theory accounts
for antibiotic resistance and pesticide resistance. And Darwin's triumph
is a theory, a rational way of organising observations, ideas, and mechanisms
to guide future observations, thought, and action. The exhibition includes
a wise and important video in which scientists discuss what theory means
in science as opposed to casual speech. In the video, Eugenie Scott
asserts: “Theories explain laws and facts. They're the most important
thing we do in science.”
The words and images on display at the exhibition are available to
anyone with an internet connection. They tell a coherent, comprehensive,
and intellectually insightful story of the growth of evolutionary ideas
and explanations in Darwin's mind. All the exhibit labels, many illustrations,
pictures of many of the objects, and much of the video content can be
downloaded for free.
Then why, when I went to the exhibition on a Sunday morning just after
the museum opened, was there a large crowd waiting to enter? Because
the objects on display are simply thrilling. I found Darwin's handwritten
notes especially affecting. In one notebook, Darwin wrote: “for such
facts undermine the stability of species” and then, with prudence, he
inserted a carat after “facts” and wrote “would” above the line to make
it read: “for such facts would undermine the stability of species”.
The manuscript makes it clear what he really thought in a way no printed
transcription could.
 Some
of the objects assembled have not been together since they left the
Beagle on Darwin's return to England in 1836. Darwin's study in Down
House is reconstructed, and a first edition of On the Origin of Species
lies on his work table. His walking stick leans against his rolling
easy chair. One can imagine that Darwin has just stepped into the other
room for a moment.
For me, the biggest excitement was seeing the original B notebook of
1837–38 opened to the page on which Darwin wrote, “I think”, and then
drew a tree of life branching from a common origin. I have used a reproduction
of that figure in lectures, and Eldredge uses an excellent photograph
of it as the frontispiece of his beautifully illustrated and perceptively
written book. Nothing matches seeing the original.
The exhibition does not, however, idealise Darwin. We see, for example,
how he failed to label some birds he collected in the Gala'pagos by
their island of origin and had to rely on Captain FitzRoy's more precisely
labelled specimens. Darwin later wrote: “It is the fate of every voyager,
when he has just discovered what object in any place is more particularly
worthy of his attention, to be hurried from it.”
As I left the exhibition, I imagined what would happen if Darwin, funded
lifelong by his family's wealth, were alive today and tried to get government
grants to support his decades of empirical and theoretical research
on evolution. That research has undoubtedly changed the way we understand
the world. Darwin showed that the variation among individuals of a species
is the essential raw material on which natural selection acts. Darwin
put chance variation at the heart of the dynamics of evolution, and
the science of chance variation in all branches of science is, without
doubt, the major conceptual advance of the last 150 years. Sorry, Einstein.
Evolution in the USA these days is associated with good and bad news.
The good news is a ruling on Dec 20, 2005, by US Federal Judge John
E Jones III—nominated by President Bush in 2002 and reportedly a Republican—that
the Dover Area School Board's requirement that intelligent design be
introduced before the teaching of evolution violated the separation
of church and state required by the Constitutions of the USA and Pennsylvania.
The school board that imposed this crypto-creationist requirement was
voted out of office. That is good news.
The bad news is that this magnificent exhibition—the most detailed
and inclusive exhibition ever assembled anywhere of Darwin's personal
effects, collected specimens, letters, manuscripts, and notebooks—has
no corporate sponsor. Foundations and individuals helped fund the exhibition.
The American Museum of Natural History's earlier exhibitions Petra:
Lost City of Stone and Einstein found corporate sponsors. Why not Darwin?
After Darwin closes in New York it will travel to other venues. If
it comes to a museum near you, don't miss it. If it does not, look at
the website and read the book. The exhibition tells the story of Darwin's
life and his intellectual journey in evolution with such beauty and
accuracy that it is essential viewing, especially in a country where
Darwin's ideas have not yet breached the bedrock.
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