PCGUIA 10/PC Guia 10.iso/database/body/cu39.txt

Text File | 1996-03-14 | 32KB | 649 lines

1.5
Francis Crick and James Watson proposed the now well-
known model for the structure of DNA, the chemical that
carries the instruction that determines heredity. In 1953
they suggested that the DNA molecule comprised a double
spiral strand, with base-groups arranged linearly along each
strand. In replication the two strands separated and
synthesised new halves identical with the old ones. Thus in
cell division one molecule of DNA would give rise to two
identical molecules of DNA so that the two new cells would
have the same set of instructions. Here was the physical basis
for Mendelian genetics, which enabled studies on the genetic
code to begin. Crick shared in the deciphering of that code,
thus meriting a second Nobel prize. He proposed on
theoretical grounds that a sequence of three bases along a
strand of RNA could code for a particular amino-acid. Since
there are four different bases this gives the possibility of
specifying 43 = 64 amino acids. (As there are only 20 amino
acids in cells there is, as we now know, a great deal of
redundancy in this "triplet code"). Soon the sequences coding
for all the acids were found. This "genetic code" is now
printed as a standard table in most biology textbooks, a
reminder of Crick's extraordinary achievement. Crick and
Watson would not have been able to unravel the code
without the earlier pioneering work of Maurice Wilkins and
Rosalind Franklin, who first identified the basic double spiral
skeleton of the DNA molecule. Watson made models based on
their findings and his realisation that the two strands could
unzip to become separate templates from which another pair
of double spirals could be built, was his greatest triumph. He
had been appointed professor of biology at Harvard by the
time he shared the 1962 Nobel prize with Crick and Wilkins
(Franklin had died), and was director of the Cold Harbour
Springs Laboratory of Quantitative Biology, Long Island,
when his famous book, The Double Helix, was published in
1968
@
2.3
Two Britons and an American were today jointly awarded
this year's Nobel Prize for medicine for work on heredity.
The Britons are Dr. Francis Crick, 46, a molecular biologist at
the Cavendish Laboratory in Cambridge, and Dr. Maurice
Wilkins, 45, deputy director of the Medical Research Council's
bio-physics research unit at King's College London.  The
American, Dr. James Watson, is Professor of Biology at
Harvard, and worked at Cambridge, England, in 1951-52.

Professor Ulf von Euler, chair of the Caroline Institute's Nobel
committee, which selects the medicine prize winners, said the
work of this year's winners was of great importance to the
whole study of heredity and the reason for the passing on of
hereditary diseases.  It may even be found to provide an
explanation for the deformities of thalidomide babies, he
said.

CODE DISCOVERED

The work of the trio, meant, in effect, the discovery of a code,
or working instructions, for the formation of enzymes which
govern heredity.  This was another link in the work of
making clear the whole "blueprint" for the production of
living beings, he said.  It could lead to an explanation of why
each individual was unique in some respect.

The official announcement said the three men had received
the award for their work in achieving a breakthrough on a
"most fundamental biological problem" - the discovery of the
molecular structure of deoxyribonucleic acid.  This is a
biological structure which makes possible the passing on of
characteristics from parents to child.

Earlier this month Dr. Crick was awarded the $25,000 (about
ú8,900) Gairdner Foundation prize.  He was also one of three
Britons who shared the 1960 Albert Lasker awards
presented in New York by medical and health organizations.
Dr. Wilkins was another of the joint winners.

Dr. Wilkins, who is on a visit to America, was born in New
Zealand and went to King Edward's school, Birmingham, and
St. John's College, Cambridge.

Dr. Watson, who is 34, was also named as one of the Albert
Lasker award winners two years ago.  A native of Chicago, he
was a National Science Foundation fellow in Copenhagen in
1951.

Asked by reporters at Cambridge Massachusetts, whether he
was surprised at getting the Nobel Prize, Dr. Watson replied:
"Somewhat, but not very."  He said he had been told that
research into heredity would win the scientists involved the
award.
@
2.4
Book review

Everyone knows that The Double Helix is a personal account,
by one of the main actors, in what the author describes as
"perhaps the most famous event in biology since Darwin's
book," a claim which the writer of the blurb on the dust-
jacket - a type of writer not usually given to understatement
- cautiously modifies to "a discovery that many scientists
now call the most significant since Mendeleyev's."

Most people know also, by now, that a rather large number
of Watson's biological colleagues are offended, some quite
deeply, by the manner in which he has treated the subject.
The editor of Nature pathetically confessed:

"Before 'Nature' abandoned the attempt to complement the
literary appraisal which will be published next week by a
scientific opinion, no fewer than a dozen distinguished
molecular biologists had declined an invitation to review the
book, usually on the grounds that they were too close to the
subject, too far away from it or too busy."

That is enough to make any biologist-reviewer look to his
own credentials.

Is it a work of psychological insight which for the first times
makes it possible for the general reader to realise what it
feels like to be a productive and even creative young
scientist in a major centre like Cambridge?  Well, a little Yes,
but mostly No.  One surprise is the demureness of the picture
Jim paints in one of his sub-themes - how he used to make
time to go and drink sherry with au pair girls at the boarding
house run by Camille Prior, one of the most formidable
Establishment hostesses of Cambridge.  In my day, the tough
Thirties time of the Depression and the Spanish War, we
certainly didn't make do with sherry in drawing-rooms.

Still, there are, so far as I know, very few descriptions of the
scientist's life which give even as much of this feeling as
Watson's book does.  Needham's essay "Cambridge Summer),
is perhaps the neaerest to filling the bill, and to making the
essential point that creative young scientists are, neaerly
always, inhabitants of a demi-monde, a Bohemia, which has
only the most uneasy of relation with the established world
of Fellows of colleges and university staff.

There has been more writing about this sort of situation in
connection with painting than with science; but more usually
by painters themselves.  In this aspect, "The Double Helix" is
quite comparable to that charming work "Picasso and his
Friends" by Fernand Olivier, or even "Life with Picasso" by
Francoise Gilot.  And one finds that the comments which
Picasso, a hundred per cent concentrated on his own line,
would make about say, Matisse, who was on a different line,
are little less biting than some of the opinions Jim Watson
throws out about his colleagues and competitors. But perhaps
Picasso was a little smoother; one of the major criticisms of
Watson is that he seems to be some way towards the maniac
egocentricity exhibited, in the world of painting, by Salvador
Dali in his autobiographical works "In Modern Art" and
"Autobiography of a Genius."

And so we come to the major issue. Is the event that Watson
chronicles the most significant discovery since Darwin (or
Mendel); and does his account show us "how creative science
really happens"?  The short answer is that Jim Watson is
writing about  only the very final stages in a scientific
advance which had been put firmly on the rails long before
he came on the scene; but what he and Crick worked out in
1953 turned out to be enormously more suggestive than
anyone had a right to expect, and led to an almost fantastic
effloresence of new biological understanding,  most of it
dominated by the incisive intelligence of Crick. The actual
"creative process" by which the 1953 "breakthrough" was
achieved does not, however, in my opinion rank very high as
scientific creation goes.

The major  discoveries in science consist  in finding new
ways of looking at a whole group of phenomena. Why did
anyone ever come to feel that the structure of DNA was the
secret of life? It was the result of a long battle. Right up to,
and beyond the Crick-Watson breakthrough of 1953,
biological orthodoxy held that the most important
characteristic of living things is that they can take in simple
food-stuffs and turn them into complicated flesh.

It was back in the late  Twenties that a few geneticists,
particularly  H.J Muller, began to urge that this view is
inadequate, and that the real "secret of life" is to be sought in
the hereditary material - not only what it is, but how it
works. By the late Thirties there was a small group of
adozen or so who had developed this subversive point of
view to the state where one could begin formulating
questions definite enough to be answerable. I was myself on
the periphery of the group; the important ones were
geneticists like Darlington in this country, Ephrussi in Paris,
Timofeef-Ressovsky in Berlin; a few physicists, like Delbruch;
and in particular, crystallographers like Astbury and Bernal.

It was this group which changed the whole direction of
fundamental biology from a concentration on metabolism to a
focus on genetics; and they pointed out that the genetic
material consists of protein and DNA, though they could not
tell at that time which was the more important; and finally
they suggested that the most promising way to investigate
the structure of the material was X-ray crystallography. The
work of this group was almost totally disrupted by the
second world war, but their message was widely
disseminated by the physicist Schrodinger, living in Ireland,
in his elegant little book "What is Life?" published in 1944.
During the war years another major step had been taken by
Avery, who showed that of the two constituents of the
genetic material, is is the DNA, not the protein, which is
crucially important.

So when Crick and Watson in Cambridge, and Wilkins and his
associates in London, began  working, the critical stage of
asking the right questions had been accomplished. DNA was
as Watson puts it, "up for grabs," and one could look on the
search for its structure as a race, to be played with no holds
barred.

This is a rather abnormal situation in important science, and
the overwhelming importance which Watson gives to "getting
there first" is a violently exaggerated picture of what is
usually an important but by no means dominating
preoccupation of active scientists. Moveover, even in
connection with DNA, getting there first was not so important
in the long term. DNA plays a role in life rather like that
played by the telephone directory in the social life of London:
you can't do anything much without it, but, having it, you
need a lot of other things - telephones, wires and so on - as
well.

It might have been - and Watson and Crick were aware of
the possibility - that the structure of DNA would be as barren
of suggestion as the enteries  in a telephone  directory.
Watson records his "delight and amazement, the answer was
turning out to be profoundly interesting." The real
importance of the Watson-Crick-Wilkins structure was not
simply that a race had been won against Pauling or any
others, but much more that it suggested a whole series of
new and fruitful questions about how it operates biologically
- and Crick with his colleague, Sydney Brenner, has played a
major part both in asking and answering them.

Not only was the situation Watson describes, of a highly
competitive race for a well-defined goal, rather unlike the
conditions in which most science is done, but also the type of
thinking he used is not typica l of most science. Watson
approached DNA as though it were a super-complex jigsaw
puzzle; a puzzle in three dimensions and with slightly flexible
pieces.

Solving a puzzle like that demands very high intelligence,
and Watson gives a vivid blow by blow account  of how he
did it. But this is not the sort of operation that was involved
in such major scientific advances as Darwin's theory of
evolution, Einstein's relativity or Planck's quantum theory.
And one is struck by how little Watson used a faculty which
usually plays a large part in scientific discovery, namely
intuitive understanding of the material.

I will mention two examples, one more technical, one
concerned with more abstract logic. When Watson was trying
to fit together certain molecules,  known as thymine and
guanine, known to occur in two alternative forms, he just
copied the shapes out of a chemical textbook and had not a
trace of technical intuition as to which shape was more
probable.

Again, on the more abstract level, the whole of genetics is
concerned with one thing turning into two, or occasionally
two turning into one; the number three never comes into the
picture. Yet Watson spent a lot of time trying to work out a
three-stranded structure for DNA. The very idea of threes
would make all one's biological intuition shudder. Of course,
intuition can be drastically wrong; but it is usually astrong
guide in innovative thinking.

Watson's book, then, gives a vivid and exciting account of a
dramatic episode in modern biology. The episode was
enormously important, not so much because it led to the
discovery of the structure of DNA, but because the structure
discov ered turned out to be extremely suggestive of further
lines of advance. But the situation he describes o well is not
typical of most top-level science, either as an example of the
sociology of science or in the type of thought process
involved.
@
2.5
JUST 30 years ago in a pub by the Cavendish Laboratory in
Cambridge two unorthodox young scientist announced that
they had discovered the secret of life.  Their official report
which appeared in the journal Nature was rather more
reticent.  It proposed a chemical structure for a complicated
substance found in living cells.  The only reference to any
wider implications was a brief passage which read:  "It has
not escaped our notice that the specific pairing we have
postulated immediately suggests a copying mechanism for
the genetic material."  The authors were James Watson and
Francis Crick.  The paper described their double helix
structure for the genetic material DNA - deoxuribonucleic
acid, organic matter resembling string which can only be
seen under the microscope.

Of the two reports the one delivered in the pub was the more
honest.  For the discovery immediately explained one of the
central problems of biology: how genetic information is
stored and copied so that it can be passed on from one
generation to the next.  Last week the 30th anniversary of
the double helix was celebrated in Cambridge with a
conference organised by Nature.  "We deserved the Nobel
Prize because we knew how important DNA was," Watson
told the conference, with none of the reticence that
characterised his and Crick's original paper.

The double helix, with its two intertwined spirals of DNA
which can unwind and separate, both becoming moulds for
exact copies of the original double helix, was one of those
flashes of insight which, like Newton's laws of gravity,
suddenly unifies a whole body of existing knowledge.  And it
triggered off a burst of creativity with few parallels in the
history of science.

In the ensuing three decades all doubts that DNA is the
material from which genes are made have been removed.
Most of the mechanism of inheritance has been worked out
at the most fundamental, molecular level.  The code whereby
information is stored in the genes had been cracked, the
chemical processes through which this information Is
translated and put into effect to control the workings of the
living cell have been identified.  Knowledge of DNA itself has
become so detailed that it is possible to point to a single
chemical unit among the thousand million in the human
genes and say that it is a mistake here that causes a disease
like sickle cell anaemia, or to write down the complete
chemical formula of the genes of a simple virus.

But what use is it all?  For the first 20 years the DNA
"researchers" only answer was that fundamental
understanding of basic biological processes had to pay off one
day.  Not that they cared very much whether it did or not so
long as research funds were forthcoming.  The sheer
intellectual excitement of it all was enough.  Then in the
early Seventies came the discoveries of American scientists
like Herbert Boyer, Stanley Cohen and Paul Berg, which
opened up a range of practical applications for DNA research
as dazzling as the intellectual ones of the original discovery.

They demonstrate as vividly as the outcome of early
research on the atom the impossibility of foreseeing where a
fundamental discovery will lead.

These new discoveries were not unifying insights but a set of
techniques: for chopping up the long spirals of DNA with the
chemical equivalent of scissors, sticking fragments together
again in arrangements that never occur in nature, and
introducing these artificial DNAs into the cells of bacteria and
other organisms.  They make it possible to splice, say, a
human gene into a chemical factory for making some scarce
biological product.

This kind of genetic engineering is already being used to turn
out things like insulin and interferon cheaply and in
quantity, and for making ultra-safe vaccines.  It can improve
the efficiency of the organisms used in existing biological
processes like fermentation, and create new ones tailored for
specific jobs such as destroying dangerous pollutants.

Related techniques make it possible to detect early in
pregnancy the defective genes in the foetus responsible for
diseases like thalassaemia.  The mother can then be offered
an abortion.  Genetic disease detectable in this way may soon
include cystic fibrosis and muscular dystrophy.

Within the last year or two scientists have isolated from
human tumours bits of DNA which appear to be capable of
causing cancer, but to be present in healthy people too.
Nobody yet understands what is going on, but it could lead to
the identification for the first time of the primary events
when a cell turns cancerous.

But 30 years on there are still two major unsolved mysteries
connected with DNA.  One is how genes are switched on and
off so that cells containing identical sets of genes can form
things as different as nerves, bones, skin and muscle.  The
other is how DNA-based life ever got started.  No one has yet
been able to suggest how it could have evolved through
simpler forms that might have arisen by chance to the
incredibly complicated system we find today.  The problem is
so difficult that Crick seriously espouses the theory that life
did not originate on earth at all but came from outer space.

Perhaps that particular problem will never be solved, but
Watson and Crick's discovery is now undeniably established
as one of the central insights of biology.
@
2.6
Advanced biotechnology refined genetic engineering will be
much more widely used in medicine in the 1990's. Today's
treatments will begin to be replaced by the most natural of
all possible therapies, the substances the human body makes
and uses to combat disease. Work on a variety of techniques
is being done all over the world.

Natural curative substances will be produced outside the
body by human genes implanted into cell cultures grown in
bio-reactors. A rising number of bio-pharmaceuticals, all as
potent as interferon or insulin, will be harvested in this way.

New antibiotics are urgently needed to attack, among other
things, the hospital  "superbugs" which have become
resistant to all existing antibiotics. A second generation, made
by genetic engineering, will be coming on the market. These
will have been produced by introducing new genes into the
moulds and other organisms that produce antibiotics, making
hybrid antibiotics which could never be produced naturally.

The body's natural defences against disease, human
antibodies, will increasingly be made outside the body by
genetic engineering. They will become cheap and be widely
available and will be used to diagnose and treat diseases
including cancer.

Antibody therapy is among the most natural forms of
treatment, since it uses only the human body's natural
defences against disease. Catalytic antibodies, or abzymes,
made to act like natural enzymes, will be used as new
medical drugs able to destroy blood clots. These will prevent
coronary heart disease, soften and remove scar tissue, or
perform other tasks in ways no existing drugs can match.

Vaccines made by genetic engineering to protect against
malaria should be in widespread use by 2000. So, with a bit
of luck, will be vaccines against AIDS, although drugs able to
cure this condition are unlikely in the next 10 years.

Some of the new bio-pharmaceuticals will be extracted from
the milk of farm animals, such as cows or sheep, grown from
eggs with human or other foreign genes implanted them.
Herds of such transgenic animals will be grazing in
pharmaceutical farmyards by the turn of the century. These
animals will also have been made disease-resistant by other
added genes and,  contrary to the fears of animal-rights
activists, should enjoy unusually well-protected lives because
of their very high value.

By 2000 attempts will have begun to treat diseases caused
by genetic defects by implanting into the sufferer healthy
genes to take the place of defective ones. And it should have
become easier to prevent the birth of handicapped babies by
the use of sophisticated pre-natal tests.

By that stage, another extraordinary development will be on
the horizon the growing of new limbs or organs to replace
those lost in accidents or wasted through disease. This will be
made possible by stimulating genes that are normally active
only during embryonic development.
@
2.7
Few scientists would seek to start serious work in a new field
at 60, and few would be given the opportunity.  But Francis
Crick's solution to the problem of growing old in science has
been just that.  Nine years ago, he ended a 30-year sojourn in
Cambridge to join the Salk Institute in Southern California,
and decided to think properly about the brain.  The motive
was simple: "Because it's a lot of fun".

Now nearly 70, Crick still gives the impression that being
active in science is the most fun you can have.  And by his
account he has found the ideal conditions to carry on.  The
sun shines, he is well paid, has no specific duties, and can
work as he pleases.  "It's difficult to convey how nice it is
working there."

But perhaps there are other motives besides financial
security and fun.  It would surely have been difficult to
sustain the level of his contribution to the subject he helped
found just after the war - molecular biology; not because his
stature has diminished but because of the enormous scope of
the subject as success has prompted expansion.  For many
years, as richly documented in Horace Judson's history of the
subject in The Eighth Day of Creation, Crick was the universal
catalyst in studies of how genes and proteins work at the
molecular level.  Judson quotes another great theoretician,
Jacques Monod: "No one man discovered or created molecular
biology.  But one man dominates intellectually the whole
field because he knows the most and understands the most.
Francis Crick."

For a deeper motivation, go back to Crick's re-entry into
research after war service designing mines for the
Admiralty.  Although trained as a physicist, his strong
materialist conviction drew him to two new areas - how
genes worked, and the problem of consciousness.  Both
seemed to offer a chance of removing the mystery from
biology.  He plumped for genes, then, but the other interest
remained.  And the same optimistic atheist, still convinced
science must make its own way forward without reference to
other belief systems: the Crick who resigned his founding
fellowship of Churchill College, Cambridge, when they built
the college chapel.

Returning to neurobiology now carries the echoes of the state
of molecular biology immediately before and after the war.
As Crick sees it: "It's in a very primitive and simple state.
It's rather like people in the 1920s and 1930s trying to
imagine what the structure of a gene should be.  "But it was
not possible to wait any longer for light to dawn - when he
decided to go to California he was mindful of his age; "I
thought if I was going to make the change I'd better get on
with it."

Not that Crick's powers show any serious decline.  The sandy
hair is now white, but he is still the tall, lean, garrulous
figure who directed the traffic of ideas in molecular biology
for so long.

Crick is not the cartoon Crick of Watson's stylised memoir
The Double Helix, with its famous opening: "I have never
seen Francis Crick in a modest mood." It is a Crick still deep
in the business of science, and eager to talk about the field
which now fills his thoughts.

And a remarkably complex field it is. The few pounds weight
of grey matter in our heads contains around one hundred
thousand million neurons - the building blocks of the
nervous system.  And each neuron is linked to as many as
ten thousand others, and influences them through a
combination of chemical and electrical signals.  Although the
system's speed of operation at the level of cellular messages
is slow compared with human-built computers, its richness of
interconnection still makes a myriad of tasks which leave
computers looking stupid so simple for us we rarely realise
how remarkable they are - seeing, hearing, speaking or
listening all remain essentially mysterious.

But of course Crick's attitude to neurobiology is shaped by his
deep knowledge of a molecular biology, as well as being
influenced by the same underlying metaphysical conviction.
His own focus is on the visual system, partly because it is the
subject of a long tradition of work in the field, partly because
he has a sense it may be possible to make progress here.
And Crick is not especially interested in "black box"
descriptions of vision, or in whether it can be successfully
modelled with some electronic device - he wants to know
how it actually works in the brain; "you have to think in a
very different way - once you've got away from the idea that
there's someone inside you head looking at what's going on.
You have to explain how it is that you perceive things is all
done by neurons firing.  It's a very , very strange thing."

One product of his research was an assault on human
dreaming.  A widely publicised joint paper in Nature two
years ago proposed that the function of dream sleep is "to
remove certain undesirable modes of interaction in networks
of cells in the cerebral cortex," through a mechanism of
reverse learning.

This paper, which Crick now seems to regard as a bit of a
sideline, nevertheless bears all the hallmarks of his scientific
style: there is a carefully constructed theoretical argument -
there needs to be a way of activating spurious links between
neurons, and modifying the connections so they are less
likely to recur; the argument is tightly linked to evidence
about sleep and about properties of neural networks; it is
elegantly expressed - "we dream in order to forget," the
authors write at one point.  All it lacks is any way of testing
the proposal rigorously by experiment.

It also shows why his style is often unpalatable to non-
scientists.  The dreams paper is fascinating to read, but puts
forward ideas which rob the nocturnal images we remember
of any meaning.  By this argument, the dreams which stay in
the mind are aberrations, failures to erase nonsense
messages in an information processing system.  It is this
treatment of problems which have wide popular resonance -
the origin of life, the nature of inheritance, consciousness,
dreaming - in what Crick regards as a properly scientific
spirit which makes one believe the feeling he describes in
Life Itself, that a modern scientist lives in a different culture.

In some ways, he now finds it easier to find common ground
in chance encounters.  He recalls how 20 years ago you could
go to a party in Cambridge and talk to a perfectly intelligent
person who didn't even know the sun was a star."  That
happens less often now, but it is still hard to put across the
thinking behind work in progress, especially work on the
brain where we have many problems and few solutions.

On a more philosophical level, he now takes a long view. "If
you want to establish that dualism is wrong, for example, it's
not going to be done in a short time - there will be many tens
of years of work." Even in molecular biology, the reductionist
approach is not completely secure, though there is every
reason to be confident. "We can see how powerful it is to
have genes producing proteins and proteins interacting...but
we couldn't answer someone who was extremely sceptical
because we  just don't have detailed answers. We couldn't
say how you build a hand."

But again the difference in lookin g at the brain is that we do
not yet see how such a problem could be answered. As Crick
puts it, we have not yet found the right idiom for solving
problems of brain function. Artificial intelligence research
has been helpful, but chiefly in showing how complex
faculties like vision are. And even if there are hints about
how to solve problems of vision for machines, they do not
look to Crick as though they are going to be the same as the
solutions which have evolved in side the head, "any more
than the flight  of aeroplanes is exactly like the flight of
birds".

If the hope of progress in brain research stretches far into
the future, Crick's own scientific life clearly can not. But he
intends to remain active in the field for a while yet. He gives
the impression of preparing to grow old, but he is certainly
not ready yet. And while he is prepared to debate the merits
of returning to London when he finally retires, perhaps to
write a book on the brain, he also avers that he and his artist
wife Odile now feel like natives in California.

His career has spanned an extraordinary era in biology. The
science-obsessed Mill Hill schoolboy who began work as a
physicist before the war can now look back on a string of
remarkable successes in unravelling the intimate workings of
the cell. Along the way, he acquired a Nobel prize, for the
solution of the double helix with which his name will always
be linked, and a kind of celebrity. (He relates with a grin how
he did not have the heart to tell the Cambridge publican who
showed him the helical plant frame in his garden that he had
built a wrong-handed helix.)

Yet for all the changes the last 40 years have seen, his own
pattern of work has remained unusually stable. He has
taught little, and never directed any large-scale research. He
declares himself allergic to committees, and turned down a
couple of Cambridge masterhips because they involved all
the things he did not like. In a way, it has been an indulgent
life, talking, reading and writing - and Crick can talk on a
sparkling variety of subjects. But the indulgence has always
been underpinned by a fecundity of ideas and intellectual
zest rarely matched in any field. No doubt the luminosity of
Crick's intelligence has dimmed some-what since he first
started to exercise his talent for solving problems of
biological gadgetry. But that seems no reason to stop work
altogether. Asked to describe his role in neurobiology today,
he laughs and recommends asking others how they see him.
"My point of view is that I'm having a good time."