The term Biochemical Evolution is used to describe the evolution of the biochemical processes and components of living organisms, such as the structure and function of biologically important molecules, metabolic pathways, subcellular structures, and cells. Although a relatively new subject, this field of research has already received great interest from both academia and industry because the principles and theory behind biochemical evolution have enormous potential in the creation and development of new biologically active compounds, drugs, and treatments for disease. However, almost every book that discusses evolution has ignored the role that biochemical evolution plays, and so in his new book, Athel Cornish-Bowden attempts to fill the knowledge gap for students, professional scientists and all interested individuals. In The Pursuit of Perfection the author explains how the biochemical processes that occur in living cells, long thought to be evidence of intelligent design rather than evolution, can now be understood as the result of natural selection. For example, the initial impression that metabolic pathways consist of an almost haphazard collection of reactions that happen to do the job turns out to be quite false. When detailed studies are made to see how the actual organization of a process compares with other ways of achieving the same result, the one found in living organisms is found to be the best possible, or at least very close to it. The style, content and organisation of the book are intended to make the book accessible, interesting, and fun to read for both scientists, students, and scientifically-minded individuals.