The most important scientific breakthrough in modern times

came in 1944 when O.T. Avery and two colleagues discovered DNA. This mysterious substance is the basis of all life on earth…DNA determines the nature of every living organism from the ameoba to man.

In The Genetic Code Isaac Asimov traces, step by step, the scientific research that led to this great achievement. He analyzes its meaning and its consequences and, in a fascinating forecast, he speculates on how this new genetic knowledge can be used to control the physical and mental development of a future race of men.

This book bears a decidedly peculiar relationship to two of the Abelard-Schuman science juveniles, The Chemicals of Life, and The Wellsprings of Life. In the former, Asimov talked at great length about the key classes of substance involved in life—proteins, sugars, fats—but just barely managed to miss out on including the most exciting discovery in biochemistry of the 20th century, the double-helix model of DNA. He was able to rectify the omission in The Wellsprings of Life, but made up for it by must barely missing out on discussing the genetic code and how it was worked out.

Unfortunately, The Genetic Code itself was written just as the first steps in working out the specifics of the code were being taken, and only a portion of the code had been broken, so even here the complete story isn’t being told yet.

Still, it’s a good book. Asimov skips through basic biochemistry and protein chemistry as quickly as he can. In particular, I find his ultra-simplified amino acid diagrams particularly helpful. The book provides a reasonably thorough discussion of the basics of DNA replication, and has not been outdated per se over the last thirty years.