What defines who we are? For decades, the answer has seemed obvious: our genes, the "blueprint of life." In The Master Builder, biologist Alfonso Martinez Arias argues we've been missing the bigger picture. It's not our genes that define who we are, but our cells. While genes are important, nothing in our DNA explains why the heart is on the left side of the body, how many fingers we have, or even how our cells manage to reproduce. Drawing on new research from his own lab and others, Martinez Arias reveals that we are composed of a thrillingly intricate, constantly moving symphony of cells. Both their long lineage--stretching back to the very first cell--and their intricate interactions within our bodies today make us who we are.

Engaging and ambitious, The Master Builder will transform your understanding of our past, present, and future--as individuals and as a species.