The incredible life and times of biological cells.

In this month's essay, Paul Nurse recapitulates the ontogeny of one of the most important theories in the history of biology, the cell theory, which proposes that all forms of life are composed of cells. Along the way, he lays out the wondrous molecular complexities and processes that he and others have discovered in the course of their studies of the lives of cells. In particular, Nurse focuses on the mechanisms and controls of cell reproduction that ultimately allow growth, development, and evolution to occur.