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DNA ~ The Secret of Life (Episode 1) — Transcript

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0:00[Music]
0:07There are a small group of pioneers who
0:10have explored a world too small to see.
0:16What they found there has answered some
0:18eternal questions.
0:21What is life? How is it made? Why are
0:24children like their parents?
0:27Their work has triggered a revolution
0:29that may make the iron and silicon
0:31revolutions seem like footnotes in human
0:34history. This series is their story. The
0:38story of the people who unlocked the
0:41secret of life.
0:43[Music]
0:56[Music]
1:09This is DNA.
1:11What it actually looks like according to
1:13the latest scientific data.
1:17It is without doubt the most powerful
1:19substance on Earth. The order of its
1:22chemicals determines whether a child has
1:24her mother's eyes or her father's smile.
1:30Until 50 years ago, almost no one knew
1:33of its existence. But that all changed
1:35when two unknown scientists ran into a
1:37pub in Cambridge shouting that they'd
1:39found the secret of life. Jim Watson and
1:43Francis Crick.
1:47[Music]
1:52If you go to Cambridge and walk around
1:54the grand old buildings, you'll hear of
1:57the achievements of Francis Bacon,
1:59Alfred Lord Tennyson, and Isaac Newton.
2:04But if you ask about Watson and Crick,
2:06you'll hear rumors of improper behavior,
2:09skull duggery,
2:11even plagiarism.
2:15But what if you go to the people
2:16themselves? What do they have to say?
2:22Francis Crick lives in a house on the
2:24edge of the Mojave Desert in California,
2:26and he's become a little reclusive when
2:28it comes to discussing DNA. Some say
2:31it's because he's ill. Others say he
2:33finds the whole subject uncomfortable.
2:36Or maybe he's just busy with his more
2:37recent work, studying the chemical
2:39nature of dreams. Whatever the reason,
2:43he no longer gives interviews.
2:46But Jim Watson does.
2:51Today, he's a 74year-old world famous
2:55multi-millionaire,
2:57but he was just a 25year-old junior
3:00researcher when he explained life in
3:02scientific terms.
3:11Still all these years later, one gets a
3:13sense of the brash young man who was
3:15planning to overthrow the old ways of
3:18thinking.
3:23You if you looked at Cambridge, you
3:24know, we were products of God and uh
3:28Darwin wasn't uh celebrated as the most
3:31important person.
3:34[Music]
3:37the statement that uh life could be
3:40understood finally in terms of
3:42molecules. Uh people would say it was
3:44hypothesis
3:46you know until you could explain
3:49heredity in terms of molecules someone
3:51could always say there was something
3:52else. So Francis and I went united as
3:56you just thought religion was wrong.
4:00Not necessarily silly but wrong.
4:04There was no God and uh you know humans
4:08had to make our own rules and not just
4:12obey rules because someone said they
4:14came from God.
4:16You realize that you know
4:21the people you know thought we were
4:23slightly crazy
4:26but uh we didn't think we were. We
4:29thought the other people were dull.
4:33Dull or not, the other people at
4:35Cambridge didn't hold up much hope of
4:37Watson and Crick doing anything at all,
4:39let alone finding the secret of life.
4:42Watson, the awkward American kid, and
4:44Crick, a splendid talker who had never
4:47quite managed to finish his PhD. They
4:50were seen as lazy jokers.
4:53To appreciate what they did, we have to
4:56imagine ourselves in the 1950s when all
4:59that was known about life was what could
5:01be seen down a microscope.
5:04Cells dividing.
5:06They could somehow magically divide to
5:08form plants or panthers or people. But
5:12how? There had to be some kind of script
5:15or instructions telling the cells what
5:18to do.
5:19And it had to be here in the
5:21chromosomes.
5:23It was known that chromosomes were made
5:25of two discrete ingredients called
5:27proteins and DNA.
5:30Most people expected to find the answer
5:32in the proteins.
5:35Proteins are very complex and made up of
5:37many different chemicals.
5:40So they distracted the best minds.
5:44But Watson and Crick decided to look at
5:46the simpler DNA.
5:48DNA is composed of only four
5:50ingredients.
5:53They thought if they could work out how
5:54the atoms of these four ingredients were
5:56arranged in physical space, they might
5:59be able to work out what they did.
6:02They had a hunch that the
6:04three-dimensional structure might reveal
6:07its function.
6:09But while Watson and Crick had never
6:11found the structure of anything, 60 mi
6:14away in London, there were another pair
6:16of scientists who had.
6:19Rosalyn Franklin has been called the
6:22dark lady of DNA.
6:24She died without ever getting the credit
6:26for her part in the discovery.
6:29Some say she was betrayed by her
6:31colleague at King's College London.
6:33[Music]
6:38If you go to Kings along a remote
6:41corridor and down these stairs,
6:4450 years on, you'll still find her
6:47colleague,
6:48[Music]
6:50Morris Wilkins.
6:52[Music]
6:56On the walls of his office are clues
6:59which hint at what he's been through.
7:05During the Second World War, he helped
7:08to create the atom bomb.
7:11The night it was dropped on Hiroshima,
7:14he was at a party celebrating the
7:16culmination of his work when a man came
7:19up to him and said something that would
7:21change his life.
7:24>> It was being Monday when the bomb went
7:25off and he said, "I call it Black
7:30Monday. I always hoped it wouldn't work.
7:35So
7:37I sort of stood there and felt a bit
7:39small
7:40and uh then said, "Yes, I think you
7:43think you're quite right."
7:46But it did work. And so we are living
7:51uh kind of in the aftermath of that.
7:57Disillusioned with the science of death,
8:00he chose the science of life instead.
8:03And that's why he chose to look for the
8:05structure of DNA.
8:07>> Well, here is one of the X-ray
8:09generators we're using in this work.
8:12Here is the X-ray tube.
8:14>> Wilkins strange contraption is in fact a
8:16kind of camera.
8:19>> It's a technique called X-ray
8:20crystalallography.
8:23A crystalline form of DNA is placed
8:25inside the camera and when X-rays are
8:28fired through it, they scatter onto
8:30photographic paper and form a regular
8:32pattern.
8:34It's a bit like shining a spotlight at a
8:37chandelier.
8:40Light hits the crystals and then
8:42defracts onto the wall. Now imagine you
8:45can't see the chandelier and you can
8:47just see the light on the wall.
8:50From that you have to guess the shape of
8:52the chandelier
8:54and that's what these photographs are
8:57taken by Morris Wilkins. They were the
9:00first clue to the structure of DNA.
9:03But his boss realized he was on to
9:05something big and decided to bring in an
9:08expert, Rosalyn Franklin. And suddenly
9:11it wasn't just Wilkins taking
9:13photographs of DNA.
9:16So Watson and Crick were in Cambridge.
9:19Wilkins and Franklin were in London,
9:22but there was someone else lurking out
9:24there. Someone with a formidable
9:26reputation,
9:28an American called Lionus Pauling.
9:32He died years ago, but his son was
9:34involved, too. And we found him in the
9:37middle of Wales, miles from the nearest
9:40town.
9:42In this house is Peter Pauling.
9:46It's very often in science that that the
9:49times are right and people have
9:52different people have the same idea,
9:57you know, at roughly the same time
10:00and getting in first somehow is
10:03important.
10:05>> Although they didn't all realize it,
10:07these five characters were in a race.
10:10Peter Pauling knew them all and watched
10:12this piece of history unfold. His father
10:15had the best credentials, a double Nobel
10:17Prize winner.
10:18>> P did very few things by accident. He
10:22did things.
10:25He had a reason for doing things.
10:29Tapa DNA was just
10:34a substance like sodium chloride.
10:40Lionus Pauling looked for the structures
10:42of many molecules and he usually found
10:45them too. That's why in the world of
10:471950s science he was one of the most
10:50recognizable figures.
10:51>> I like to
10:54understand the world. I like to learn
10:57about new ideas but I also uh like very
11:01much uh having new ideas myself or
11:04making discoveries myself. This pleases
11:07me immensely.
11:10He had a different approach. He was
11:12going to guess the structure by building
11:15ball and spoke models.
11:17The balls represent the atoms. The
11:20spokes are how far apart they must be
11:22from each other according to the laws of
11:24physics. So Linus Pauling would then try
11:27to see how they fitted together.
11:31Solving a structure this way was like
11:34doing a three-dimensional jigsaw puzzle.
11:38So Watson and Crick had a choice to do
11:41the painstaking X-ray work or try their
11:43luck building models like Linus Pauling.
11:46For them the choice was simple.
11:49>> To build models,
11:51it was only a question when you started
11:52to build models. Would you do it after
11:55you collected
11:57years of experimental data or would you
12:00try and build the the model with a
12:03minimal data?
12:06So they went for model building with the
12:08minimum of data. Some might say a more
12:11leisurely approach, but that was the
12:14Cambridge style.
12:17And Watson and Crick seemed to be the
12:19epitome of that, whiling away the hours,
12:23chatting about the secret of life.
12:25>> People would laugh at us and say, "Oh,
12:27we weren't doing experiments. Just take
12:29these long walks and lunch and uh
12:32constantly talking." Instead of
12:35experimentally happy days,
12:41>> people see you do no experiments. It was
12:44sort of thought, you know, we were
12:45parasites. Other people did the work and
12:47we got the glory. Uh
12:51but the truth was, you know, uh uh
12:54complicated.
12:56>> In fact, Watson and Crick were asking
12:58all the right questions.
13:02What was common to all forms of life
13:06and uh
13:08what finally seemed to be common to all
13:09forms of life was
13:12there was a script.
13:15We had been thinking it was DNA but we
13:18didn't know the shape of the script and
13:20uh always the big problem was the
13:22copying. Who copied it? There weren't
13:23any, you know, little monks inside the
13:26cell copying the script.
13:31By not getting bogged down in the
13:33details of experiments, their minds were
13:35free to concentrate on the big ideas.
13:39Their constant talking was in fact a way
13:41for them to distill their theories.
13:47Three teams, three different approaches,
13:49and Watson and Crick weren't the
13:51favorites.
13:52>> I would say that
13:55Watson and Crick were number two.
13:59And at that time I would put my money on
14:03this crowd.
14:06[Music]
14:20King's College London should have been
14:22the ideal place to study DNA.
14:25But trouble was brewing.
14:27While Moraurice Wilkins blended into the
14:29shadows, Rosalyn Franklin was making a
14:32big impression on those around her.
14:34>> She was uh of of medium height and had
14:39black hair which she wore straight uh
14:42just in in no particular arrangement,
14:46but she had the most startling dark eyes
14:50which showed the intense nature of her
14:53personality.
14:55Most of the young men who worked with
14:57her were half in love with her.
15:00>> One of these young men was Raymond
15:02Gosling.
15:03At the time, he was a lowly lab
15:05assistant working for Roslin Franklin.
15:08>> Looking back on it, I think I was very
15:10privileged to have been there. Uh, I
15:14only wish I had known at the time that
15:18it was that important. I might have
15:20remembered more or worked harder and who
15:23knows I might have tried building a few
15:25models secretly.
15:27Model building was in the air. But her
15:30view was you could build models all day.
15:33But how did you prove which one was
15:34right? On the other hand, if you made
15:37the measurements, you did all the
15:38corrective geometry and you put them
15:41into the equations, you would let the
15:44data speak for itself.
15:46And out of that would come a definitive
15:49structure.
15:51>> But there was a problem. Wilkins was
15:53under the impression that DNA was his
15:55project, but their boss had told
15:58Franklin it was hers.
16:00>> No mention was ever made of the fact
16:03that Wilkins was the overarching
16:07uh person concerned in the lab. She
16:11certainly felt she was coming in, she
16:13was taking over that defraction work.
16:19So at opposite ends of the corridor,
16:22Morris Wilkins and Rosalyn Franklin
16:24worked on DNA.
16:27Occasionally, they would announce their
16:28results to the department.
16:32One afternoon in November 1951, Franklin
16:36was to reveal her latest DNA data to a
16:38select group of King's College
16:40scientists
16:42and one outsider.
16:46Well, this is where I came in
16:49early November 1951 to hear Roslin
16:53Franklin talk about her newest results
16:56on DNA.
16:58And uh I was terribly keen to know what
17:02she'd done because uh
17:05I wanted to build a model and I thought
17:07I would learn possibly something about
17:10the structure. There was probably, you
17:12know, 30 people in the room and, you
17:14know, I slipped in, you know, was
17:16inside, you know, like a spy and, uh,
17:20Roslin, you know, was seemingly much in
17:23control.
17:25I totally never took notes. My memory
17:27was good.
17:31Having taken in as much as he could of
17:33the X-ray data, Watson rushed back to
17:35Cambridge to tell Crick what he'd heard.
17:39For the next two weeks, they worked on a
17:41model. And on the 28th of November,
17:431951, Watson and Crick announced that
17:46they had found the structure of DNA.
17:49[Music]
17:54Francis rang me up and said, "We made a
17:57model. Come have a look." So, I went to
18:00the others and collected. We all went
18:02up.
18:03>> It was a pretty ugly structure. Francis
18:05liked that. I don't know. you know, he
18:07called up the people at Kings and said
18:09we' done something clever and uh
18:12I was a bit worried.
18:14>> Feeling apprehensive, the King's team
18:16left for Cambridge. Rosalyn Franklin
18:19took one look at the model and
18:21>> she laughed at them. Uh much to their
18:25discomfort, I think, had said, "Oh,
18:27look, you've got it inside out."
18:30>> Watson's memory had let him down over
18:32the amount of water in her DNA data. The
18:35water content is vital to the structure.
18:38So, their model was a complete disaster.
18:40>> Roslin was tickled pink. She was right.
18:45The building of a model of a crystal
18:47structure was a waste of time until
18:50you'd let defraction speak for itself.
18:52And that was hard work.
18:56I don't know. I mean, um, one might say,
18:58well, why not? You mean it is an
19:00exploration to make a model. I mean,
19:03make a model and if you make a bit of a
19:05fool yourself in the process, why worry?
19:07You might be be lucky.
19:11>> Well, strange thing about science is how
19:13stupid people can be so much of the
19:15time. And uh so Francis and I were
19:20really stupid.
19:23Worse than that, they had incurred the
19:25wrath of the London team's boss, Sir
19:27John Randall, who called up Watson and
19:30Crick's boss, Sir Lawrence Bragg, to
19:32complain about their behavior. And Bragg
19:35was furious. In those days, it wasn't
19:37gentlemanly to have knowledge of
19:40somebody's current unpublished work and
19:42to make use of that working on the same
19:45problem. It was rather like having an
19:48affair with his wife. I mean, it
19:50happened, but you uh you you didn't
19:52really take much credit in doing it.
19:56>> Watson and Crick were kicked off the
19:58case, and even their model building
20:00equipment was sent to Kings.
20:03>> When we gave it up, we gave them the
20:05jigs for making models, and they didn't
20:08build any. So, they never took on what
20:13we had failed to do.
20:16Watson and Crick were officially out of
20:18the race.
20:23The way should have been open for the
20:25King's College team, but one thing stood
20:28in their path.
20:31Morris and Rosalind didn't get on.
20:35Why couldn't these two characters
20:36resolve their differences?
20:39Morris was so shy that when he was
20:43talking to you and he didn't know you,
20:45he habitually talked at an angle. So,
20:49you might find that you were addressing
20:50the back of his head. I think scientists
20:52in particular tend to be rather uh
20:57um
21:00well, I don't know, sort of bottled up
21:02with um serious thoughts and uh and uh
21:07wonderful theories that uh
21:10and uh the secret of life or something.
21:14He would slide into a room and and and
21:17and mumble something and be very
21:20diffident about it. He was never going
21:21to come in and say, "Well, I'm glad
21:23you've joined my team." Uh, and and and
21:25say, "This is the way we do it." Spit
21:27spot bang. Uh, which had he done would
21:31have cleared the air.
21:32>> You know, a number of these,
21:34>> you know, he wasn't able to talk to her.
21:36>> I think there a number of people.
21:38>> Rosen was extraordinarily intelligent.
21:41Now, for that reason, she frightened the
21:44average bloke. I'm sure
21:47>> today Rosalyn Franklin is an icon.
21:50Outside a building for female students
21:52named after her. There's a statue of
21:55her.
21:57To get a better sense of what she was
21:59like, we asked her sister, who
22:01apparently sounds similar to Rosalind,
22:04to read a letter she wrote to their
22:05religious father. She argues for the
22:08importance of science in understanding
22:10the world.
22:12Science for me gives a partial
22:14explanation of life. In so far as it
22:17goes, it is based on fact, experience,
22:19and experiment.
22:21Your theories are those which you and
22:23many other people find easiest and
22:25pleasantest to believe. But as far as I
22:27can see, they have no foundation other
22:30than that they lead to a pleasant view
22:31of life and an exaggerated view of our
22:34own importance.
22:36Anyone able to believe in all that
22:38religion implies obviously must have
22:40such faith. But I maintain that faith in
22:42this world is perfectly possible without
22:44faith in another world.
22:51Um the picture to me seemed to say
22:54something about Rosalind. Rosalind has
22:58um sometimes seemed a bit sort of heavy
23:03in appearance at the I mean not always
23:06but sometimes. And I I thought, well, it
23:10would have been nice if uh uh she'd been
23:13able to sort of trip around on her toes
23:16and and uh look uh pretty and and
23:22cheerful.
23:25But I think it was it was very sad
23:27because
23:29uh we had thought we might be all able
23:31to join together, you see, in the
23:33scientific work.
23:36Um,
23:39it's uh
23:43that two sides to the the the the whole
23:46thing.
23:49[Music]
23:57Back in Cambridge, Watson was down in
23:59the dumps, banned from working on DNA.
24:03His dream of showing it was the secret
24:05of life was slipping away. But Crick had
24:08some good news. Someone was coming to
24:11dinner in Cambridge who could help them.
24:21>> Your favorite.
24:22>> Win Sharaf had never wanted to help
24:24Watson and Crick.
24:26Even at 96 years old, he was still
24:29bitter about what had happened.
24:33Shaf was an expert in the chemistry of
24:35DNA.
24:37Over dinner, Watson and Crick tried to
24:39plum him for information. They were
24:42fishing really. But that I get the
24:45impression
24:47they did all the time. I think Watson
24:49really was a fisherman. I mean, he he
24:53sort of brought the news to Crick. Crick
24:56was apparently the man who had the
24:58ideas. Well, I think we didn't like him
25:00because he
25:03sort of didn't, you know, warm up to our
25:06saying, you know, you could solve the
25:07structure of DNA by model building. You
25:10know,
25:10>> they both showed an extreme contempt for
25:13chemistry. That was what struck me. They
25:16were more like children in their
25:18behavior.
25:19>> You know, he was just a born enemy.
25:26Despite his extreme dislike for them, he
25:29did explain his charge rules that state
25:31the relative amounts of the four basic
25:33ingredients of DNA. By comparing samples
25:36from three different species, he
25:38discovered a strange correlation.
25:41No matter what the life form, the amount
25:43of A equal the amount of T and the
25:46amount of C equal the amount of G. This
25:49suggested the chemicals somehow went
25:51together in pairs. For Shaggaf, this was
25:54an interesting correlation, but for
25:55Watson and Crick, it was the first clue
25:58to the structure.
26:00>> I think DNA to him was yeah, an
26:04objective whose time had not yet come.
26:07[Music]
26:20Oh, here on on this table here.
26:25>> Oh, yes. Good. Yes. There's a unicam.
26:28Excellent.
26:30>> On this desk is the original equipment
26:33that helped reveal the structure of DNA.
26:36>> So, this is the first camera. This is
26:39the the first DNA.
26:40>> It's worth a fortune today.
26:43I mean, putting them in a frame like
26:45that, they look much better than just
26:46sort of lying on a table, don't they?
26:48The X-rays go in here. Photographic film
26:52is put on the inside here. Then that is
26:55put down around the the
26:59we
26:59>> like everything with Morris,
27:01>> there's more to it than meets the eye.
27:03>> Now, you want to say something about
27:05these? These are smallcale models.
27:08Morris had also wanted to build models
27:10based on the X-ray data,
27:13>> but Rosalind had all the best DNA
27:15samples,
27:17>> and they weren't talking. No one else at
27:19Kings really had the imagination to help
27:22him.
27:26>> At Kings, if anybody did perhaps see the
27:30overarching picture, Wilkins did because
27:34he often said, you know, we should all
27:36wake up. We should all try a number of
27:39different things instead of plotting
27:40along trying to solve the X-ray
27:42defraction pattern because we are in a
27:44race. It is an important problem and
27:48there are other people I mean there was
27:50this bogeyman sitting in America called
27:53Lionus Ping who already had two Nobel
27:56prizes not one and he was thinking about
27:59it. By now Lionus Pauling had turned his
28:02full attention to DNA. Suspiciously,
28:06this coincided with a certain young
28:07playboy traveling all the way from
28:09America to work in Watson and Crick's
28:12office. In those days, Lionus had a son
28:14who was about uh the same age as Watson
28:18and knew Watson and and uh Ping came
28:21across and came to our lab and he went
28:23and stayed with Watson and Crick
28:28and uh I think he put the fear of God
28:31into them that dad was thinking about
28:34this.
28:36I had to feel what was he doing in the
28:39laboratory of his uh father's big
28:41competitor.
28:42>> I was accused of being a double agent,
28:45but uh
28:48I don't accept that because I'd write to
28:51P and just say what I'm doing and he'd
28:55write back, you know, what he was
28:57interested in.
28:59>> And P was not only writing back to
29:01Peter, he was busy writing other
29:02letters, too. I wrote to Wilkins at
29:07King's College asking uh if I could have
29:11prints of the photographs that he had
29:13obtained, but I my effort was not
29:15successful.
29:17>> By now, King's College had this X
29:19pattern, which indicates that DNA is a
29:21spiral or helix shape. It was Rosalyn
29:24Franklin's best photo yet, but she
29:26wasn't letting anyone else see it. So,
29:29Pauling never saw the X. could he have
29:32come up with the right answer without
29:34seeing the king's data? Of course, I
29:37hoped he couldn't. Uh it wasn't until,
29:42you know, about the last day of January
29:44that Peter came in after lunch and uh
29:48had a manuscript. I had a letter from my
29:50father in December 52 saying he had
29:54proposed a structure for DNA. So I told
29:58the boys, "Oh, they rushed over and
30:01>> my stomach sank and I, you know, I was
30:03scared to death. So what was going to be
30:05in it?" Opened it and read it and they
30:08discovered, you know, that it it it
30:13was wrong.
30:16>> We wonder what got into Lionus.
30:21Pauling's model not only didn't fit the
30:24data, it also failed to explain anything
30:27about what DNA did. He had blundered by
30:31trying to get the structure with too
30:33little information.
30:36It wasn't any ambigu as to whether Lus
30:39was right or wrong. He said Lus is
30:41wrong. It's you know. So we were both
30:44pleased and a bit scared because maybe
30:47someone at Caltech group will tell
30:48Lionus this is chemical nonsense.
30:51Little did we know that you know no one
30:53at Caltech really had the courage to
30:55tell Lionus he was wrong. Lionus was
30:57like the pope. Lionus wasn't used to
30:59people saying he was wrong.
31:01>> So I've had a very fortunate life.
31:04>> I thought the people at kings should be
31:07relieved. So without being asked, I
31:09thought, well, just take the manuscript
31:11down to uh the kings.
31:14I was just bubbling over with the fact
31:15that we had another chance.
31:18Pauling had got it wrong and we should
31:21go into action fast.
31:24[Music]
31:36So, I went down and looked for Morris
31:38and didn't spot him. And someone told me
31:40where Roslin's office was. So, I went
31:42toward it and uh walked in.
31:47She wasn't there.
31:50I wasn't trying to read the letters on
31:52her desk or anything like that, but
31:53obviously I was looking around and she
31:55came in. Someone had told her that I was
31:58looking for her. She had a very negative
32:00reaction to me. Fury was rising. She
32:03didn't think I should be there. So, I
32:05got out of the room as fast as possible.
32:07And then Morris Wilkins had heard I was
32:10around. And there he was. And I said,
32:12"Oh, I I thought she was going to hit
32:14me." And he said, "Oh, I thought she was
32:15going to do that to me once." And uh so
32:19I went to he took me to his office and
32:22opened the drawer and took out a photo
32:24and there it was the cross which I had
32:27never seen and which they had basically
32:30weren't talking about. It it showed this
32:34sort of uh X type of um oxo type of um
32:40cross pattern which was an indication of
32:42a helix.
32:45>> Is that a big guy? I mean, it was the
32:48most beautiful photograph. You know,
32:50it's as if you see the most beautiful
32:52girl in the world and you're going to
32:54see her again. You know, it was great.
32:56>> If I got excited about the results, I'd
33:00to pass them on.
33:02I don't know. I think it uh I didn't
33:04feel there was any sort of bombshell in
33:06this.
33:09Well, the picture kept sort of racing
33:12through my brain and uh I wanted to be
33:15sure I had it right, so I wrote it down.
33:17It was just a
33:20a super reflection at 3.4 angstroms and
33:24boom boom boom. No one could look at it
33:27and say it's not a helix.
33:28>> And the reason that Watson realized that
33:30it was a helix,
33:31>> so you get a cross
33:34in the defraction pattern. Well, it just
33:36so happened that Crick knew this bit of
33:38X-ray defraction theory. And I told
33:41Watson that an X indicated a helix.
33:44>> Crick's mind was able to absorb bits and
33:47pieces from all over the place. And now
33:49this was paying off for them.
33:51>> You know, I felt, you know, maybe we'll
33:54get the answer. You know, until then, I
33:56I didn't feel we were close. I felt that
33:59picture means we're close.
34:02Wilkins undoubtedly and I think if you
34:06ask him he will say that he feels that
34:08he did uh if there were any cats to be
34:11let out of any bags he he he'd done it
34:16well I suppose it's perfectly true but I
34:18think science isn't supposed to be kept
34:20in bags no more than cats I mean I don't
34:23know what he he means but uh I mean I
34:26don't like as as a scientist sort of
34:29working away and sort of saying no
34:32wasn't tell the other scientists or
34:34something. I don't think it's the way to
34:36be working. It's science ought to be an
34:39open activity and uh so you can work as
34:43as a community.
34:46Yeah. Been impossible not to build
34:48bottles in after seeing that picture.
34:53[Music]
35:06Spring came early to Cambridge in 1953.
35:10Watson and Crick had been given official
35:12permission to return to their work on
35:14DNA, and by now they'd managed to
35:17acquire all the information they needed.
35:20Franklin's photo suggested DNA was some
35:23kind of helix.
35:25Shagg's data suggested the four
35:27chemicals in DNA might go together in
35:30pairs.
35:31But what was the structure? What was
35:34DNA?
35:36The Cavendish shop was to build us some
35:38tin models and that took too long. And
35:42uh you know finally in desperation I
35:45made some out of cardboard.
35:48I sort of finished the job on Friday and
35:51didn't get back into the cavendish
35:54probably until much before 9:30 on
35:57Saturday morning.
36:01So I came in the morning and I began
36:03moving them around and I wanted an
36:05arrangement, you know, where I had a big
36:08and a small.
36:12So how did you do it? Somehow you had to
36:17to form link bonds. So here's A and
36:22here's T. And I wanted this hydrogen to
36:27point directly at this nitrogen. So I
36:28had something like this.
36:33So then I went to the the pair and
36:35wanted this nitrogen to point to this
36:37one. I went like this. Boom. They look
36:40the same.
36:43And you can put one right on top of the
36:46other.
36:48[Music]
36:54The two together make the same shape and
36:58can go on top of each other like the
37:01steps in a staircase
37:04or to form a helix,
37:06a spiral staircase.
37:13So you could have a small one, a big
37:15one, a small one, any sequence.
37:17If you knew the sequence of one, we knew
37:20the sequence of the other.
37:25We knew we could just, you know, even if
37:27we go up to the ceiling, we were
37:28building a tiny fraction of a molecule.
37:35[Music]
37:36100 million of these base pairs in one
37:40molecule. So unbelievably
37:43all united by this either AT or TA, GC,
37:48CG all fitting into this wonderful
37:51symmetry which we saw the morning of
37:54February 28th, 1953.
37:58What they had was a double helix, a
38:02structure that revealed far more about
38:04the way life works than they could ever
38:06have dreamed of.
38:08They've been looking for something that
38:09could divide just like cells do. And it
38:12was easy to see how a double helix could
38:15unwind and form two more double helixes.
38:19They've been looking to see if DNA was
38:21the script or instructions for all
38:23living things. They realized that the
38:26millions of G's, A's, T's, and C's must
38:29be written in some kind of code, the
38:32script of life. And they even saw how
38:35the script could be copied exactly.
38:38As the double helix unwinds, each of the
38:41letters forms a new pair. And because A
38:44always goes with T and G always goes
38:46with C, the resulting two pieces of DNA
38:50are exact copies of the original,
38:53enabling the script to be passed from
38:55cell to cell and ultimately from
38:57generation to generation.
39:02It was clear now DNA was the molecule
39:05that controlled all living things.
39:09Watson and Crick ran straight to the pub
39:11where the locals were going to find
39:13their news hard to believe.
39:16>> It was hard to contain the fact that,
39:18you know, maybe we had a gigantic
39:21breakthrough. We' done something really
39:24important. We had discovered the secret
39:26of life.
39:29You could say that day was the beginning
39:31of the new genetics.
39:34They had the idea, but now they wanted
39:36to check that it was right. They set
39:39about building a tin model as quickly as
39:41they could, cross-checking their
39:42coordinates with the king's data. It all
39:45fitted.
39:47Then we had to tell the people at Kings
39:49and uh
39:52we were a bit apprehensive because we
39:54didn't want to say, "Well, we've beaten
39:56you."
39:58You have to remember that I'd been up
40:00before and seen the model that was
40:01wrong.
40:03Uh,
40:05and that gave us a buzz and a high. And
40:07then you go up there and you see this
40:09thing. It looked right when you saw it.
40:13It was so brilliantly,
40:16elegantly
40:18simple. I thought, "Oh my god, we got
40:21scooped."
40:22Because I really thought we were going
40:24to come up with something like that
40:26ourselves.
40:28It was terrible, you know, poor Morris.
40:31>> I I said that the double helix was a uh
40:36somewhat similar to a a young baby
40:41standing there all alive and saying, "I
40:44I don't care uh what you say or what you
40:48think. Um I know I am right."
40:54Rosalyn would have been appalled to
40:57learn
40:59that they had taken quite so much
41:03uh detail of her current work and put it
41:07into their model.
41:08>> I thought you know we behaved as sort of
41:11the
41:12average person would behave and uh we
41:15just thought the people at Kings haven't
41:17done the obvious thing. Why didn't they
41:19try using their data with asking what
41:23the molecule wanted to do?
41:27Rosalyn Franklin kept her distance from
41:29the other characters in this story. She
41:32spent her time working alone in her lab.
41:36People have wondered how close she got
41:38to finding the structure of DNA. The
41:40only way to know is to visit this
41:42archive in Cambridge where her notebooks
41:45are kept. Her notes suggest that she
41:48nearly got there. In one of her final
41:51entries, she is thinking in terms of a
41:53twochain or double helix,
41:57but that's as far as she got. She died
42:00just 5 years later without ever being
42:02told the extent to which Watson and
42:04Crick used her data. And when the Nobel
42:07Prizes were awarded for the discovery,
42:09she didn't get one because Nobel prizes
42:11aren't awarded postuously.
42:15People that knew her say that what she
42:17cared about most was that her work moved
42:20science forward. It was one of the few
42:23things she had in common with Morris
42:25Wilkins. Without their work, Watson and
42:28Crick could not have built this model.
42:31And the model was just the beginning.
42:35Over the next two decades, scientists
42:37delved into the molecular world of DNA
42:40and discovered how it actually controls
42:42life. But the person who did more than
42:45anyone to unravel its mysteries was a
42:48genius called Francis Crick.
42:52Today he's at the Sulk Institute,
42:54California. In one interview he did talk
42:57about what for him came after the double
42:59helix. It involves thinking beyond what
43:02he calls the narrow limits of normal
43:05human experience.
43:07Now when you want to understand the
43:09world you have to go you have to go
43:11beyond those narrow limits both in up
43:14and down both in space and time and then
43:16you find that there's a uniformity and
43:19extraordinary things happening which you
43:20had no idea of just looking at the world
43:23and it's this is the fascination of
43:24science really I think to uncover so
43:27much which is not apparent just in
43:30everyday life.
43:34Today we can see the molecular world.
43:38This is a computer representation of DNA
43:41based on accurate data.
43:44It's a long way from ball and spoke
43:46model building.
43:49What was apparent was that everything in
43:51the molecular world is more strange and
43:54sophisticated than anyone had thought.
43:57>> Biological systems are the result of
44:00evolution and they produce very
44:01complicated things. Now the reason that
44:04DNA look looks so beautiful and simple
44:06is it goes right back to near the
44:08origins of life where things had to be
44:11simple but if you actually look at the
44:13actual process of DNA replication
44:16it isn't at all the way that it we used
44:18to describe all sorts of funny things
44:21happen you have to have proteins which
44:23will unwind the helix and nick it and
44:25then join it together again you get an
44:28enormously barack complicated
44:31apparatus which one might say molecular
44:34gadgetry which actually does the job.
44:37>> This is how the chemical code of DNA
44:40copies itself. But Crick was focusing on
44:43what the DNA code ultimately did and
44:46that involved unpicking the gadgets of
44:48the molecular world.
44:50>> What's sometimes called reverse
44:52engineering, it happens in the in the
44:54commercial world when one firm produces
44:57a gadget and another firm buys it and
44:59tries to take it to pieces and find how
45:01it works. That's called reverse
45:03engineering. But in our case, it's
45:05reverse engineering what you might call
45:07a foreign culture.
45:10>> As a result of that process, it's
45:12possible to see how DNA makes living
45:15things. How a simple code is turned into
45:18flesh and blood.
45:23The blue molecule racing down the DNA
45:26unzips the double helix and copies one
45:29of the two strands.
45:32This copy is then released for the next
45:34stage of the process.
45:40The yellow copy feeds into another
45:43machine which deciphers the code and
45:46orders up the right components one unit
45:48at a time from the surrounding chemical
45:51soup.
45:56The product of this machine is protein.
46:00This could be a thousandth of an
46:01eyebrow. The same process could make a
46:04tiger's claw or part of the wings of a
46:07dove. It's the same for all life.
46:11What is made is all down to the DNA, the
46:14specific order of the chemical code.
46:19And today, these machines can read the
46:21DNA code. How a person is made is being
46:25revealed. How a brain is built is being
46:28explained in the G's, A's, T's, and C's.
46:32They are beginning to read differences
46:34in our characters and personality.
46:46Um the genetics of of human nature
46:52is slowly unfolding.
46:55>> Even our story can be seen in this way.
46:58The fate of our characters determined by
47:01their individual natures.
47:04>> I thought the problem would last me my
47:06lifetime. I had no idea it would be
47:08solved within 20 years.
47:11You see, I was I mean it was
47:13embarrassing almost to got to the stage
47:14where instead of this problem lasting
47:16for one's life, one had to look around
47:18for another problem.
47:20So now Francis Crick is trying to find
47:22out how the brain works. He has always
47:25just been interested in making new
47:27discoveries.
47:31Jim Watson is president of Cold Spring
47:33Harbor Laboratories.
47:35He's built a house on the grounds with a
47:37statue of the double helix in his
47:40garden.
47:43He gives lectures arguing for the
47:45benefits of genetic engineering.
47:50There are people who say, "Well, we're
47:52playing God."
47:56And you know, I have a straightforward
47:58answer. If we don't play God, who will?
48:02Yeah.
48:10[Music]
48:17and Morris Wilkins couldn't be more
48:19different.
48:20[Music]
48:23Having worked on the atomic bomb, he
48:25chose to study DNA because he thought it
48:28wouldn't be controversial.
48:31Today, as the newspapers talk of
48:33creating designer babies and the birth
48:35of human clones, he lectures at King's
48:38College London about the social
48:40responsibility of science.
48:43He hopes the human race will use this
48:46knowledge wisely.
48:49[Music]
49:07[Music]
49:28[Applause]
49:29[Music]

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