Rosalind Franklin: DNA's unsung hero - Cláudio L. Guerra

1,569,114 views ・ 2016-07-11

TED-Ed


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The discovery of the structure of DNA
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was one of the most important scientific achievements in the last century,
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in human history, in fact.
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The now-famous double helix is almost synonymous with Watson and Crick,
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two of the scientists who won the Nobel Prize for figuring it out.
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But there's another name you may know, too,
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Rosalind Franklin.
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You may have heard that her data supported Watson and Crick's brilliant idea,
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or that she was a plain-dressing, belligerent scientist,
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which is how Watson actually described her in "The Double Helix."
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But thanks to Franklin's biographers,
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who investigated her life and interviewed many people close to her,
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we now know that that account is far from true,
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and her scientific contributions have been vastly underplayed.
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Let's hear the real story.
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Rosalind Elsie Franklin was born in London in 1920.
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She wanted to be a scientist ever since she was a teenager,
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which wasn't a common or easy career path for girls at that time.
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But she excelled at science anyway.
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She won a scholarship to Cambridge to study chemistry,
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where she earned her Ph.D.,
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and she later conducted research on the structure of coal
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that led to better gas masks for the British during World War II.
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In 1951, she joined King's College
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to use x-ray techniques to study the structure of DNA,
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then one of the hottest topics in science.
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Franklin upgraded the x-ray lab and got to work
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shining high-energy x-rays on tiny, wet crystals of DNA.
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But the acadmemic culture at the time wasn't very friendly to women,
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and Franklin was isolated from her colleagues.
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She clashed with Maurice Wilkins,
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a labmate who assumed Franklin had been hired as his assistant.
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But Franklin kept working,
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and in 1952, she obtained Photo 51, the most famous x-ray image of DNA.
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Just getting the image took 100 hours,
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the calculations necessary to analyze it would take a year.
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Meanwhile, the American biologist James Watson
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and the British physicist Francis Crick
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were also working on finding DNA's structure.
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Without Franklin's knowledge,
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Wilkins took Photo 51 and showed it to Watson and Crick.
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Instead of calculating the exact position of every atom,
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they did a quick analysis of Franklin's data
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and used that to build a few potential structures.
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Eventually, they arrived at the right one.
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DNA is made of two helicoidal strands,
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one opposite the other with bases in the center like rungs of a ladder.
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Watson and Crick published their model in April 1953.
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Meanwhile, Franklin had finished her calculations,
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come to the same conclusion,
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and submitted her own manuscript.
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The journal published the manuscripts together,
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but put Franklin's last,
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making it look like her experiments just confirmed Watson and Crick's breakthrough
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instead of inspiring it.
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But Franklin had already stopped working on DNA
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and died of cancer in 1958,
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never knowing that Watson and Crick had seen her photographs.
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Watson, Crick, and Wilkins won the Nobel Prize in 1962
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for their work on DNA.
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It's often said that Franklin would have been recognized by a Nobel Prize
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if only they could be awarded posthumously.
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And, in fact, it's possible she could have won twice.
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Her work on the structure of viruses led to a Nobel for a colleague in 1982.
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It's time to tell the story of a brave woman who fought sexism in science,
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and whose work revolutionized medicine, biology, and agriculture.
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It's time to honor Rosalind Elsie Franklin,
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the unsung mother of the double helix.
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