Your Inner Fish: A Journey into the 3.5-Billion-Year History of the Human Body

by Neil Shubin

What is it about a hand that seems quintessentially human? The answer must, at some level, be that the hand is a visible connection between us; it is a signature for who we are and what we can attain. Our ability to grasp, to build, and to make our thoughts real lies inside this complex of bones, nerves, and vessels.

It is no exaggeration to say that this was a fish-eat-fish world. The strategies to succeed in this setting were pretty obvious: get big, get armor, or get out of the water. It looks as if our distant ancestors avoided the fight.

So, like a building made of bricks or concrete, bones are shaped so as to maximize their compressive functions and minimize twisting and bending, something Galileo recognized in the seventeenth century.

Without these protective caps at our joints our bones would grind against one another: a very unpleasant and debilitating outcome of arthritis.

If you know how to look, our body becomes a time capsule that, when opened, tells of critical moments in the history of our planet and of a distant past in ancient oceans, streams, and forests.

It exemplifies how the unknown should not be a source of suspicion, fear, or retreat to superstition, but motivation to continue asking questions and seeking answers.