IN SEARCH OF DEEP TIME

A persuasive as well as convivial introduction to cladistics—paleontology’s answer to the discontinuities of Deep Time—from science writer Gee (Nature magazine). For some 50 years now, as Gee explains, cladistics has been gathering adherents in the world of paleontology. This approach to fossil evidence labors against the mischief of cultural bias that informs narrative readings of Deep Time—history as measured in the millions of years. Our window into that era is fossils. Their messages are obscure, argues Gee, and we have invented, not read, their stories. The linear, progressive sense of evolution is more wishful thinking—from little brain to big brain, from knuckle-dragging to noble erect carriage—than testable hypothesis, and our search strategies are so inextricably tied to the immediate present that they prevent us from seeing, say, a feather when it looks like no feather we know. Enter cladistics, an approach that seeks patterns rather than processes in the fossil record—an inventory of shared features that plot a pattern of relatedness—capable of being tested, yet aware that the results are provisional. Gee reads the fossil record in the light of his study of ancient environments, in which feathers do not always imply flight, to suggest alternative expressions of evolutionary change. At the same time, his skepticism about the assumption that —all life on Earth shares a common evolutionary origin— and the widely accepted Principle of Parsimony (the fewer assumptions the better) provides a tonic jolt to received opinion. There is no grandstanding here, for Gee paints cladistics as a quiet revolution, not intent on throwing any babies out with the bathwater unless they turn out to be figments of our imagination. Gee’s corrective arguments at once ground his science in humility and liberate thinking about Deep Time through their invitation to chart a seamless topology of life then and now.