How does the sequence of the human genome provide a definitive record of our evolutionary history and biological blueprint? Matt Ridley, a science writer with a background in zoology, utilizes the completion of the Human Genome Project to map the twenty-three pairs of human chromosomes. He presents a narrative framework that treats each chromosome as a chapter in an autobiography, explaining how specific genes influence human development, disease, and behavior.

The work is widely regarded as a foundational text for popularizing complex genetic concepts for a general audience. Its structured, chapter-by-chromosome approach provides a clear and accessible entry point into the mechanics of human biology.