Discovering the Double Helix

Question: What was the key breakthrough that led to the discovery of DNA?

James Watson: Well, there were two.  A methodological one, where we borrowed from Linus Pauling, that the most direct route to the structure was building molecular models as opposed to trying to deduce the structure entirely from x-ray defraction data.  There was a decision that Crick and I made in October, 1951. 

The second was the realization that the data of Erwin Chargaff showing similar amounts of adenine and thymine and timing and of guanine and cytosine indicated that they must be paired to each other in the DNA structure.  Once you had that, in fact the structure followed within several weeks. 

Question: Did your inability to find a date at Cambridge contribute to your discovery of DNA?

James Watson: The best thing that ever happened to me was I didn’t find a date because that would have... you know, the right girl I would have found more interesting than the, you know.  If I had a girl to play tennis or something, I would have preferred doing that than just, you know, thinking about DNA.  Whereas my great advantage was, I was at the time the only person truly obsessive about DNA.  And you know, so many people were just obsessive about some unrealized you know, emotional problem.  So at Cambridge University, I mean, today Cambridge University is filled with, you know, well-dressed, attractive, intelligent girls.  The two Cambridge colleges when I was there, the girls were out of town, we virtually never saw them and you know.  It was just lucky it was for a later time in my life.

Question: Have you been happy with the progress in molecular biology since you discovered DNA?

James Watson: Well, initially I wanted to you know, move on from the structure of DNA to RNA and that didn’t seem to fall out, so that was a disappointment.  But on the whole, it was that everything occurred faster than we thought it would.  That you know, we had the genetic code, the first details in '61, and its completion by '66.  That was only 13 years.  And I never thought it would go so fast. 

And then, I never even dreamed, you know, that we would be able to sequence long stretches of DNA. You would actually see the structure of specific genes.  Then we were likely thinking in terms of small viruses because we knew they contained only several genes.  And so maybe the ultimate would be to some day work out the structure of a sequence of a virus containing several thousand letters.  But once it started it just has moved, you know, with always... You know, we had the method before we almost had the questions to ask about what we were seeing. 

Recorded on September 28, 2010
Interviewed by Paul Hoffman

The pioneering molecular biologist recounts some of the major breakthroughs in the search for the structure of DNA.

Why a federal judge ordered White House to restore Jim Acosta's press badge

A federal judge ruled that the Trump administration likely violated the reporter's Fifth Amendment rights when it stripped his press credentials earlier this month.

WASHINGTON, DC - NOVEMBER 16: CNN chief White House correspondent Jim Acosta (R) returns to the White House with CNN Washington bureau chief Sam Feist after Federal judge Timothy J. Kelly ordered the White House to reinstate his press pass November 16, 2018 in Washington, DC. CNN has filed a lawsuit against the White House after Acosta's press pass was revoked after a dispute involving a news conference last week. (Photo by Alex Wong/Getty Images)
Politics & Current Affairs
  • Acosta will be allowed to return to the White House on Friday.
  • The judge described the ruling as narrow, and didn't rule one way or the other on violations of the First Amendment.
  • The case is still open, and the administration may choose to appeal the ruling.
Keep reading Show less

How to split the USA into two countries: Red and Blue

Progressive America would be half as big, but twice as populated as its conservative twin.

Image: Dicken Schrader
Strange Maps
  • America's two political tribes have consolidated into 'red' and 'blue' nations, with seemingly irreconcilable differences.
  • Perhaps the best way to stop the infighting is to go for a divorce and give the two nations a country each
  • Based on the UN's partition plan for Israel/Palestine, this proposal provides territorial contiguity and sea access to both 'red' and 'blue' America
Keep reading Show less

Scientists just voted to change the definition of a kilogram

The definition of a kilogram will now be fixed to Planck's constant, a fundamental part of quantum physics.

Greg L via Wikipedia
Surprising Science
  • The new definition of a kilogram is based on a physical constant in quantum physics.
  • Unlike the current definition of a kilogram, this measurement will never change.
  • Scientists also voted to update the definitions of several other measurements in physics.
Keep reading Show less