In this exciting work on the cutting edge of scientific knowledge, Henry Gee, Chief Science Writer at Nature, tells the story of a recent revolution in palaeontology. For the first time, all of us can share in the wonder of a deceptively simple idea known as cladistics, the science of comparison. The cladistics revolution is transforming almost everything we know about the science of life in Deep Time -- the billions of years in which life has evolved on this planet. It provides insights and solutions to questions about ourselves ordinarily considered beyond the realm of science.
What can we truly know of the awesome dark chasm of Deep Time that separates us from the beginning of life on earth? In Search of Deep Time strips away conventional assumptions about the evolution of life to reveal a bizarre world that is truer to the facts -- and far stranger -- than many Darwinians and certainly any Creationists ever imagined. Scientists used to categorize life forms according to how similar they looked. If an animal had a wing, it was a bird; if it had a fin, it was a fish. But then, is a penguin a bird? Is a whale a mammal? While the answer to these questions is yes, it doesn't mean much scientifically. The real answers to how life evolved and how life forms are related come from cladistic analysis, from measuring the tremendous variety of genetic and anatomic variations between species and juggling them with computer technology. Because of cladistics, scientists have come to believe that hippos are more closely related to whales than pigs. We have learned that the old way of understanding nature, in which we squashed the teeming variety of life on earth into our own haphazard and arbitrary categories, must be replaced by understanding precisely how similar, and how different, each species measurably is. Rather than a hierarchical tree of life with ourselves at the apex, we now see a bush with evolutionary branches intertwining in strange and surprising ways -- mushrooms really are closer cousins to us than plants are.
Gee journeys among the scientists who are making the breakthrough discoveries about the evolution of life. He travels to a fossil dig in Kenya with Meave Leakey of the pioneering palaeoanthropology family that made the Rift Valley in East Africa famous as the origin of modern humans. There he finds a small fossilized skull, and considers whether anyone could ever know if that fossil was the remains of Gee's great-great-great-great-great-, etc., grandfather. The answer is clearly no. There are no knowable ancestors in Deep Time. Beyond the last few dozen generations, all individuals in the entire animal kingdom, indeed all individuals throughout the epochs of Deep Time in all the kingdoms of life on earth, are cousins. Whether in Eastern Africa or in his native London with palaeontology's "Gang of Four," Gee offers lively explorations of the idea that there is no knowable descent of man. Throughout, he displays the crackling wit and exceptional command of his field that readers of his articles in Nature have admired for years. He takes you to the places where science is happening and becomes the perfect guide to a scientific adventure of the mind.
In Search of Deep Time shines a light on age-old controversies about fish with fingers and dinosaurs with wings, but also reveals the scientific facts of problems we have only begun thinking about. For instance, how will we recognize life inside a rock on another planet if we should ever find it? Cladistics ultimately leads Gee to a surprisingly profound question: What if there were another hominid species to compare ourselves with? Perhaps the science of comparison, cladistics, is the only way we will ever really come to terms with who we are, because real knowledge can only be based on comparison. Gee illuminates a shift in the history of science that is happening now and is changing our understanding of what scientific knowledge is. More deeply, it is changing our understanding of who we are.