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Chapter 6
Themes
and Colors
Key
LitCharts assigns a color and icon to each theme in The Double Helix, which you can use to track the themes throughout the work.
Research, Adventure, and the Thrill of Discovery
Scientific Collaboration, Competition, and Community
DNA and the Secret of Life
Academic Life and the University
Summary
Analysis
As soon as Watson met Francis Crick, he knew he wanted to stay at Cambridge. They were both enthusiastic about DNA, and they thought they could discover its structure before Linus Pauling. They spent endless hours talking, and Crick explained Linus Pauling’s alpha helix research to Watson. Pauling’s discovery wasn’t based on equations or X-ray diffraction, but rather on a straightforward analysis of how different atoms fit together, using molecular models. Watson and Crick realized that they could do the same thing with DNA.
Watson and Crick’s friendship was the foundation for their research. In turn, their friendship depended on their shared curiosity about DNA, similar scientific ambitions, and compatible personalities. These factors didn’t just amuse or delight Watson—rather, they gave him a deep sense of purpose and belonging. On another note, Linus Pauling’s alpha helix research was a suitable model for Crick and Watson’s work because it was essentially theoretical. In other words, Pauling’s work showed Crick and Watson that they could bypass experimental work entirely and simply use logical deduction to build a molecular model of DNA. This was welcome news because they didn’t have the time, experience, or resources to perform complex experiments.
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Watson and Crick started building molecular models and trying to fit them together in a helix (the simplest and most likely structure for DNA). Based on the tight DNA crystals that Maurice Wilkins and Rosalind Franklin studied, Watson and Crick assumed that DNA probably included multiple long chains of nucleotides, which were twisted and bonded together. They also knew that DNA contained four different nucleotides, which had the same phosphate and sugar groups (so they would bond in a consistent way) but different nitrogenous bases (so they would be distinct from one another). This was perfect for a helix structure: the nucleotides could all have the same kind of bond but occur in the very irregular order that’s necessary for a series of genes to form a code.
Readers might assume that little was known about DNA when Watson and Crick started studying it, but this wasn’t the case at all. In fact, when Watson and Crick started their research in 1951, scientists had known about and been conducting experiments on DNA for almost a century. These earlier experiments were the foundation for Crick and Watson’s research—as this section shows, earlier work allowed Crick and Watson to make a number of key assumptions about DNA’s structure. However, Watson and Crick didn’t just want to explain how DNA was structured—they also wanted to prove that it was the key genetic material. In order to prove both these points, they had to solve a crucial puzzle: how can DNA be a regular molecule that forms the same shape in every organism and yet encode irregular genetic information that is different in every organism?
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Watson and Crick also knew that they could eliminate plenty of possible structures for DNA if they had good X-ray pictures of it. But the only person with these pictures was Maurice Wilkins. Fortunately, Wilkins was happy to visit them at Cambridge. He explained that he also thought DNA was a helix, but he spent most of his time talking about his worsening feud with Rosalind Franklin. She wouldn’t even share her results with him anymore. The three men agreed to attend her upcoming talk.
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