The order of fossils in the world’s rocks is powerful evidence of our connections to the rest of life. - Neil Shubin

Humans are a timekeeping species, and much of our history can be traced to the ways we parse the moments of our lives.

What do billions of years of history mean for our lives today? Answers to fundamental questions we face—about the inner workings of our organs and our place in nature—will come from understanding how our bodies and minds have emerged from parts common to other living creatures. I can imagine few things more beautiful or intellectually profound than finding the basis for our humanity, and remedies for many of the ills we suffer, nestled inside some of the most humble creatures that have ever lived on our planet.

Our fish ancestors had internal and external nostrils, too, and to nobody’s surprise these are the same fish that have armbones and other features in common with us.