Decoding Four Billion Years of Life, from Ancient Fossils to DNA
Starred review from October 28, 2019
Making complex scientific ideas both accessible to and enjoyable for the general public is a rare skill, but one that Shubin (Your Inner Fish), a University of Chicago biology professor, has mastered in his eloquent survey. He explores two complex and related evolutionary questions: how organisms bearing no immediately perceptible resemblance to each other—such as dinosaurs and birds—can be closely related; and how new traits—such as feathers or lungs—can appear. Writing for a lay audience, Shubin takes a historical perspective and describes the gradual accumulation of scientific knowledge. He explains that Darwin, without possessing the data available today, grasped that body parts evolve through “a change in function.” In recent years, genetic testing on fish with lunglike organs has revealed that “lungs aren’t some invention that abruptly came about as creatures evolved to walk.” Instead, lungs already existed in certain species of fish, but changed function when their descendants became land-dwellers. Shubin also covers discoveries about the genetic mechanisms behind such changes, such as studies pinpointing the specific areas in DNA that turn genes on and off during fetal development. This superb primer brings the intellectual excitement of the scientific endeavor to life in a way that both educates and entertains.