This book is a history of how the molecular structure and biological function of DNA were gradually determined over a period of about a century before the Watson-Crick double helix announcement in 1953. The structure and function of DNA are treated, but only in a peripheral way. The focus of the book is on the steps and the struggles in the investigation of DNA, the good and the bad theories, the important turning points, and the personal stories of the small army of scientists who were involved in one way or another. History of science, but with a lot of human interest.
The book is worth looking at just for its front matter, which includes a detailed timeline listing the dates of important points in the history, and a Who’s Who which lists 29 of the main scientists, along with birth and death dates and thumbnail biographical sketches. There are also many good photos and illustrations, and a fine glossary of the technical terms.
The range of subjects investigated as part of the DNA story is amazing: orchids, pus cells, garden peas, fruit flies, X-ray diffraction, Bessel functions, hydrogen bonding, a lot of difficult chemistry…And the range of personalities and life experiences of the scientists is also fascinating.
The book reads almost like a detective story. For example, it was found that dead bacteria could transform the genetic characteristics of live bacteria – how did that happen? Another example: chemical analysis of DNA showed that the amounts of adenine and thymine were always equal, as well as cytosine and guanine. Now, any biology textbook today will tell you that the DNA base “A” always goes with “T” and “C” goes with “G”, but that used to be a mystery. It was obvious that having equal amounts of A and T and C and G just HAD to be important, but why in heaven’s name?
Along with all the successes in the scientific work, the book also tells about mistakes and bad guesses along the way. The following are some of the dead ends: the belief that DNA had no part in genetics – proteins did everything; the bitter fight against Mendelian genetics; and the belief that DNA consisted of just four nucleotide subunits instead of millions. Probably the strangest error was Linus Pauling’s proposed DNA structure. He was one of the world’s best chemists, but he came up with a structure that was judged absurd. “Not even wrong.”
So if you are interested in the history of science, this is a great book.