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

Why do we look the way we do? What does the human hand have in common with the wing of a fly? Are breasts, sweat glands, and scales connected in some way? To better understand the inner workings of our bodies and to trace the origins of many of today's most common diseases, we have to turn to unexpected sources: worms, flies, and even fish.

Neil Shubin, a leading paleontologist and professor of anatomy who discovered Tiktaalik—the "missing link" that made headlines around the wor…