The Double Helix By James D. Watson

The Double Helix is one of the most interesting and also most detailed books that I have read so far. It is a personal account of the discovery of DNA by no other than James Watson himself. In this novel James narrates the events from when he first becomes interested in DNA to the discovery itself.

James D. Watson has never been naturally interested in DNA; he had even avoided chemistry or physics. His journey into DNA first began with chemistry when his Ph. D. supervisor, Salvador Luria, sent him to learn chemistry in Copenhagen. He was not Luria’s choice at first but when she knew that her friend, theoretical physicist Max Delbruck, wasn’t able to learn chemistry, he sent James. He was sent to biochemist, Herman Kalckar once in Copenhagen. However, James barely understood Herman and so, had to resort to follow his close friend Ole Maaloe, who had study phages in hope of finding how genes control heredity.

On a trip to Naples, for a macromolecule meeting, was when Watson’s interest in DNA had begun. Maurice Wilkins had sparked his desire when he had shown his X-ray diffraction picture of DNA. As James grew more interested, he wanted to learn how to solve diffraction pictures, which drove him to work in the lab in Cambridge University in Cambridge, England. Watson shared his enthusiasm for DNA with Francis Crick who also worked at the lab. They began to talk a lot of DNA including how it was made up of four different nucleotides. They also believed that the DNA molecule must be a helix mainly because Linus Pauling’s alpha helix was a helix. Linus Pauling had been the one that discovered the alpha helix and also whom Watson and Crick set their mind to beat in the race to the discovery of DNA structure.

As time passed, Watson and Crick made their first model of what might a DNA molecule looked liked. This model consisted of salt bridges that held the phosphates of a three chain DNA molecule together, but this model was objected by Rosalind Franklin, who was the only woman scientist working with them and a talented crystallographer. And also when Maurice saw it, they found out that it was clearly wrong. Watson then began to work with the tobacco mosaic virus (TMV) because DNA was a big part of the virus. It was not long before he learned how to take X-ray pictures of TMV samples. After taking many samples, finally Watson had gotten the X-ray pattern to prove that the DNA structure was a helix. But Rosalind went against this idea too, saying that DNA was not a helix based on her data. Watson quickly reported his results to Crick the following day. Afterwards, Watson found out that the number of adenine always matches the number of thymine molecules in DNA, and the same for guanine and cytosine molecules. This piece of valuable information was first acquired by biochemist Erwin Chargaff before finding its way to the lab.

Later into the novel, news had been received that Linus Pauling had beat them to the discovery of the structure of DNA. Watson quickly grew anxious but once more information had been received, he learned that there was an error in the structure and it was that phosphates never contain hydrogen bound atoms. When Watson went to tell Rosy the news, she showed him an X-ray photograph of DNA in B form. He quickly went to tell Francis that they are very close and began to build two chain molecules of DNA instead of three.

With the information from the B form photograph, Watson started building two chain models with the sugar-phosphate backbone in the center. But reasoning caused him to begin placing the sugar-phosphate backbone on the outsides. With that settled Watson then started working on the bases. He matched adenine with adenine and did the same with the other bases. However, when Jerry, a crystallographer, learned what he done, he was told that he was wrong. And so Watson began to pair adenine with thymine and cytosine with guanine. This conformed to Erwin Chargaff’s findings about the number of bases and also is more reasonable then pairing the bases that are the same. At once, they began to spread the word and before they knew it scientists began to rush into their lab to see the model. After endless years, Watson and Crick had finally done it, even beating Linus Pauling to it.

This book is, without doubt, related to many scientific concepts. One concept is of course, DNA. DNA or deoxyribonucleic acid and its components are a hugely related to this novel. And without it this book wound not even exist. Throughout the novel endless use of crystallography is used to hopefully identify the structure of the DNA double helix. Also endless research by other scientists in the novel also contributed to the discovery of the DNA structure. The nitrogenous bases, cytosine, thymine, adenine, guanine, that make up the DNA structure are also an important concepts in this novel. For example, when Watson realized that the “like-with-like pairing.”(Pg. 196) of the bases wouldn’t work, this shows that nitrogenous bases are related to this novel. Not only that but also the sugar-phosphate backbone is another important concept.

Viruses are also an important concept in this novel. To learn more about DNA, James had to resort to the tobacco mosaic virus because “A vital component of TMV was nucleic acid,”(pg. 110). They were considered to be “naked genes”(Pg. 22) and so scientists thought that it would be the best way possible to learn about DNA.

This novel and its author changed society and genetics dramatically. The discovery of DNA brought a whole new light into science. Many answers began to unfold such as how characteristics are inherited which has been a question long unanswered. Also the discovery of DNA allowed scientists to learn more about inherited diseases and how to cure them. Not only that but also DNA has provided evolutionists a great deal of information. The discovery helped evolutionists understand more of how we got to where we are now by leading to the development of the idea that humans were originally from Africa and then migrated to different continents. Also it has helped understand the evolution of other animals as well.

Not only has the discovery of DNA changed science but it has also changed society. One way is that it has changed society is the way crimes are solved. With the discovery of DNA, also came forensics, which decreased risks of wrong accusations. Not only that but also it enabled us to create genetically modified crops which has a dramatic changed on agriculture and also to our food supply. Genetic engineering has also affected medicine, allowing for better medicine and vaccines to be created for diseases. In addition DNA makes testing for paternity possible. It has even influenced movies.

Furthermore, now you know about the novel, The Double Helix by James Watson. Also some scientific concepts involved in the book. And more importantly how the book and author affected society and also science.

Sources:http://www.independent.co.uk/news/science/23-ways-that-dna-changed-the-world-598877.html