A collection of eight original essays that make up a primer on evolution.
Beginning with an explanation of how scientists work, Tattersall, curator of Human Evolution at the American Museum of Natural History and author of Becoming Human (1998), etc., moves on to the mechanism of evolution, and our changing ideas about it—entirely Darwinian in Darwin’s time, still Darwinian at the core. He stresses that living creatures, including humans, are not finely engineered organisms with every component perfectly adapted to its function. They are complex and clever, yet often clumsily improvised, owing as much to chance as to ingenious adaptation. There’s no denying that humans are unique, but even our most dazzling cerebral powers did not spring up full-blown. Our sense of ourselves as individuals is an example. It turns out we can teach apes, our closest cousins, to recognize themselves in a mirror. They were the first species capable of making that connection—even monkeys can’t. Halfway through, Tattersall turns to our immediate ancestors and asks the traditional question: What is the single change that set our ancestors apart from apes and placed them on the path to becoming human? Big brains and clever hands were leading candidates until a few decades ago. Today almost all experts agree that walking upright made the difference. Hominids walked for millions of years before Homo sapiens appeared a hundred thousand years ago. Soon after, the fossil record blossoms with evidence of painting, sculpture, music, notation, sophisticated, decorated tools, and elaborate burial rituals. These all result from the capacity for abstract, symbolic thinking, which differentiates modern humans from those that came before. Clearly something important occurred in the evolving brain, yet the modern big brain had existed for thousands of generations before this cultural explosion.
There are plenty of strong personal opinions here (Neanderthals were a dead-end species; human evolution has stalled for the foreseeable future), but they ring true. The whole production is as absorbing and literate as one would expect from Tattersall.