Darwin famously described evolution as an elegantly branching tree of life. But as scientists have pursued molecular phylogenetics—the process of "reading the deep history of life and the patterns of relatedness” from DNA sequences—they’ve found that nature is more complicated, that life’s branches cross and converge and tangle in previously unsuspected ways. Quammen, the author of more than a dozen books of popular science, including Spillover and The Reluctant Mr. Darwin, explains how the study of DNA led to the key discovery of horizontal gene transfer: that genes can be transmitted between organisms that aren’t parent and offspring; outlines its implications; and profiles the lives and work of its principal researchers, including Carl Woese, Lynn Margulis, and Tsutomu Watanabe.
