Defending the Cavewoman: And Other Tales of Evolutionary Neurology

Much in the manner of Oliver Sacks, neurologist Klawans (Why Michael Couldn't Hit, etc.) uses stories from his clinical practice as jumping-off points for discussion of how the brain works, and of how and why it evolved as it did. Klawans explains how doctors find out which half of your brain controls your speech, and why they might need to know; how a professor's stroke cost him his ability to read, and how he regained it. Later chapters lay out ""how literacy changes the brain"" (among other things, it teaches us to use abstract categories) and how mad cow disease alters it (by means of contagious proteins called prions). Bringing in modern European history, Klawans connects an obscure nerve disease to conditions in Nazi-occupied Norway. Straying into evolutionary genetics, he describes Cheddar Man, a specimen of early Homo sapiens found in England; his DNA matches that of a modern-day history teacher still living in Cheddar. The difference between the two Cheddar men shows how much human life has been controlled by cultural, rather than biological, evolution. Klawans strikes an admirable balance between breezy narrative and serious exposition, between clinician's anecdote and broad biological overview. His decision to build each chapter around a single patient gives some of his work the feel of short stories, each with a single scientific punch line. Readers familiar with similar science writers will zip through Klawans's work with pleasure; those new to the genre will learn lots of neuroscience, nontechnically and without pain. (Jan.)