Thomas Henry Huxley (1825–95), “Darwin’s bulldog,” and his grandson Julian Huxley (1887–1975), the first director of unesco, were dominating figures of modern biology. That was especially so in biology as perceived by the public, as they were exceptionally talented at public communication. T. H.’s coining of the word “agnostic” and Julian’s promotion of the word “transhumanism” are signs of their ability both to anticipate and to influence the direction of ideas. A joint biography situating them in their times is a promising project. With The Huxleys: An Intimate History of Evolution, Alison Bashford succeeds in telling a revealing story of the transmutation of thought within and beyond biology over a crucial century and a half.

Comparing the lives of the two writers reveals a number of changes to what animal biologists were interested in over the century from 1850 to 1950. T. H. Huxley usually preferred his animals dead and was interested in skeletons, measurements of brain cavities, and comparative anatomy. Julian, by contrast, was an initiator of the turn towards animal behavior and ecology—the studies of living animals in their relations to one another and their environments. His main early scientific project, before he turned to a life of what would later be called science communication and entrepreneurship, concerned the courtship rituals of the great crested grebe, a waterbird known for its elaborate mating displays. From the point of view of evolutionary theory, the displays are very mysterious because they take place afterthe