We are taller, heavier, healthier, and longer lived than our ancestors; our bodies are sturdier, less susceptible to disease in early life and slower to wear out. These changes have occurred in all parts of the world and are continuing to occur, though not all at once and not all at the same speed; they have accumulated, generation by generation, and together constitute a major and surprising change to the human body. It is not as dramatic as the evolutionary changes that produced Homo sapiens, but it has occurred far more rapidly, within the course of about twelve to fifteen generations, from the beginning of the eighteenth century.

This book has described, and sought to explain, these changes and their causes and consequences. Its central thesis is that, over those generations, the process, which we have called technophysio evolution, has allowed many – although certainly not yet all – parts of the world to escape from hunger and disease. This has allowed men, women, and children to live longer and healthier lives and, at the same time, to enhance their own productivity and thus to contribute to the ability of our societies and economies to produce more material goods, to enjoy more leisure, and to nurture healthier and more productive succeeding generations. The process of industrialization that began in western Europe in the eighteenth century has allowed human beings to reach further toward the achievement of the potential which resides in every human body; economic growth and human ingenuity have given us the technological potential to underpin that achievement and to ensure that it continues.