I recently had the great pleasure of reading Bill Bryson’s new book, The Body: A Guide for Occupants. It’s classic Bryson: a fascinating, well-told, hilarious overview of how the seven octillion atoms in every one of us make us what we are. Being a nonscientist, what jumped out at me was just how much about basic anatomy and human biology remains a mystery. Why do we have fingerprints? No one knows. The same goes for sinuses, even though they take up a lot of room in our heads. Speaking of heads, brains across the world shrunk by about 150 cubic centimeters (about the size of a tennis ball) at the end of the last ice age, a diminution nobody can explain. And finally, despite plentiful theories, we still don’t understand why we age.
