Carl Zimmer presents a history of our understanding of heredity in this sweeping, resonating overview of a force that shaped human society--a force set to shape our future even more radically.

She Has Her Mother's Laugh presents a profoundly original perspective on what we pass along from generation to generation. Charles Darwin played a crucial part in turning heredity into a scientific question, and yet he failed spectacularly to answer it. The birth of genetics in the early 1900s seemed to do precisely that. Gradually, people translated their old notions about heredity into a language of genes. As the technology for studying genes became cheaper, millions of people ordered genetic tests to link themselves to missing parents, to distant ancestors, to ethnic identities. . . .