Publisher's Weekly Review

"What makes you and me individual human beings is not a unique set of DNA but instead a unique organization of cells and their activities," according to this revelatory study. Developmental biologist Martinez Arias's first book for general readers pushes back against the notion that genes are "the architects of our bodies," pointing to the case of triplets who shared a genetic mutation for a cleft lip that manifested differently in each sibling--the cleft was on the right side for one sibling, the middle for another, and the third had a cleft palate--despite all three having identical DNA. What actually explains how individuals develop are cells, which he contends are "master builders" that use the raw "materials" of DNA to construct organisms and have "the ability to learn, move, and count, to measure space and time." To illustrate, he describes how during the early stages of embryonic development cells exchange chemical signals to symmetrically distribute eyes, ears, and arms, revealing an ability to organize geometrically that cannot be accounted for by DNA. Martinez Arias's novel thesis invigorates, and the lucid scientific discussions will hold readers' attention even through involved examinations of how cells respond to specific proteins. This is the perfect complement to Siddhartha Mukherjee's The Song of the Cell. Illus. (Aug.)