http://www.nytimes.com/2006/07/11/science/11book.html
July 11, 2006
Books
A Peek Into the Remarkable Mind Behind the Genetic
Code
By NICHOLAS WADE
Francis Crick is associated with two discoveries, probably two of the
most important in the 20th century: the double helix of DNA and the
genetic code. The first he discovered with James Watson; the second he
worked out mostly by himself, though with contributions from many
others.
Despite Crick's extraordinary distinction as a scientist, little has
been written about his life aside from his brief autobiographical
essay, "What Mad Pursuit," and his leading role in "The Eighth
Day of Creation," Horace Freeland Judson's outstanding oral
history of molecular biology.
The first biography of Crick, who died in 2004 at the age of 88, has
now appeared. Called "Francis Crick, Discoverer of the Genetic
Code," it is by Matt Ridley, one of the few journalists Crick was in
the habit of talking with. Mr. Ridley has created a vivid portrait
that explains Crick's scientific work with clarity, deftly outlines
his career and provides sharp insights into the nature of Crick's
remarkable creativity.
Crick, who set a high value on his privacy, seems not to have left
biographers a great deal to work with beyond what is already on the
record.
One source of new material developed by Mr. Ridley concerns Crick's
wartime career in the British Admiralty. Trained as a physicist, Crick
worked on magnetic and acoustic mines and mine countermeasures.
Intelligence agents learned that the German minesweepers known as
Sperrbrechers carried an enormous magnet to make British magnetic
mines explode harmlessly far ahead of them.
When a Royal Air Force plane photographed a Sperrbrecher with its wake
cutting through the wash of a mine explosion, Crick realized he had
the physical information to calculate the weight and strength of the
magnet. On that basis he designed a mine so insensitive it would
detonate only right under a Sperrbrecher.
He had considerable trouble persuading British admirals to invest in a
mine that all other ships passed over unscathed. But that obstacle
overcome, his devices worked splendidly, sinking more than 100
Sperrbrechers and stripping German waters of their defenses.
Rejecting a promising career in military physics after the war, Crick
was influenced by two friends, the Austrian mathematician Georg
Kreisel and the physicist Maurice Wilkins, to begin a new career in
biological research.
As Mr. Ridley notes, Crick was in middle age when he embarked on his
career of scientific discovery, in contrast with the many scientists
who make their marks when young.
Crick forged his own path through life. Mr. Ridley dwells only briefly
on Crick's heterodox views and experimental way of life. He seldom
read newspapers, because working in intelligence had convinced him
that most stories never reached the press. He experimented with
marijuana and LSD, Mr. Ridley reports.
Crick and his wife Odile held lively parties and enjoyed the company
of their many bohemian friends, like John Gayer-Anderson, who made
pornographic pottery.
"Though they did not have an explicitly 'open marriage,' Francis
was an incorrigible flirt," Mr. Ridley writes, "and Odile at least
affected not to mind."
Crick refused to meet the queen when she visited Cambridge's new
Laboratory of Molecular Biology because he disapproved of royalty, and
he declined a knighthood. He deeply disliked religion, saying once
that Christianity was all right between consenting adults but should
not be taught to children.
He refused to attend weddings or funerals, though he was always up for
the party afterward. He resigned from Churchill College when it
decided to build a chapel like any other Cambridge college.
Desire to undercut religious obscurantism was a cogent motive in
Crick's scientific career, shaping his choice first of the gene and
later of consciousness as problems that, if cracked, would destroy the
last refuges of vitalism.
"Throughout, he stayed true to himself: ebullient, loquacious,
charming, skeptical, tenacious," Mr. Ridley writes in an eloquent
coda. "He would have liked to find the seat of consciousness and to
see the retreat of religion. He had to settle for explaining
life."
Among the many virtues of this short, beautifully written book are the
sharp glimpses it offers into a mind of remarkable creativity.
An unusual aspect of Crick's work habits was that his thinking was
forged in the challenge of argument. This required a constant
interlocutor or intellectual sparring partner. Mr. Kreisel, the
mathematician, was the first holder of this unusual position, followed
by Watson for the discovery of the double helix, Sydney Brenner for
the work on the genetic code, and Christof Koch for the study of the
brain and consciousness.
"In the periods when he had no such sounding board he was visibly at
a loss," Mr. Ridley says.
Another feature of Crick's mind was that he excelled in being able
to visualize the physical relationship of objects. He could
intuitively imagine in his mind's eye the space-group symmetry of a
crystal's unit cell, meaning how far it must be rotated to look the
same again. A glance at Rosalind Franklin's X-ray photos of DNA told
him what she had not grasped, that the two parallel chains of the DNA
double helix must run in opposite directions.
"Although it is necessary to be able to handle the algebraic
details, I soon found I could see the answer to many of these
mathematical problems by a combination of imagery and logic, without
first having to slog through the mathematics," he said.
Another special feature of his approach to science was the difficult
balance he always maintained between theory and empiricism.
He tried every possible theoretical approach to the problem of how the
60 possibilities allowed by a four base triplet genetic code might
yield 20 kinds of amino acid but never trusted the answers, however
elegant. That essential caution left him open to the empirical
approach by which the code was finally broken.
He had the gift of being able to scan vast amounts of confusing
experimental data, reject parts that seemed not to fit and divine the
correct answer. Before DNA, biochemists had stamp-collected a large
number of amino acids. In 1953 Crick and Watson, in sessions at the
Eagle pub in Cambridge, set out to select some finite number of amino
acids that DNA might reasonably code for.
Ridley observes: "They came up with 20. That they got the list
exactly right, despite being amateur biochemists, is a minor
miracle."
Crick's special ability to combine his intuitions with theoretical
and empirical judgment was at its finest in his astonishingly
prescient paper of 1958 on protein synthesis.
In it he laid out the field's several fundamental axioms, including
that all proteins are composed of combinations of the same 20 amino
acids, and that the linear order of amino acids determines the
three-dimensional structure into which the protein is shaped. "All
these propositions were guesses," Mr. Ridley writes, "and all are
correct."
Crick was slow to anger and quick to forgive. He was quite
unreasonably furious at "The Double Helix," Watson's deep though
gossipy account of their discovery.
The reason, Mr. Ridley suggests, is that Crick "saw himself as a
dedicated seeker of great truths who had worked very hard, with long
hours of reading, calculation, and intuition, to get to the point
where he could make a great discovery; yet the world would now learn
about the quest as if it had been just another soap opera."
But the two men were soon friends again, Crick later remarking, "I
now appreciate how skillful Jim was."
It would be unfair to criticize the author for making essentially the
same judgments about Crick's historical role as can be found in Mr.
Judson's book, for both are correct. And it would be quite wrong to
dismiss Mr. Ridley's biography because it does not contain much new
information, although in truth it does not.
Mr. Ridley's contribution is that he has extracted from
existing material a considerably more complete and colorful portrait
of Crick than has existed before. And by deft narration and analysis,
he has captured the wonder of an unparalleled scientific mind at work
and at play.