This book is an interesting exploration into the world of the ancient connection that human and fish share. We not only share a common ancestor with our primate cousins, but also with our aquatic friends. It is written by the co-discoverer of Tiktaalik, a very likely candidate for the first fish to have emerged from the oceans. It details the similarities between humans and fish, and includes detail on how a fish transformed fins into limbs and "hands".
One of the most interesting and revealing portions of this book shows the evolution of the laryngeal nerve. In humans, the laryngeal nerve takes a circuitous route, going from the brain, down into the chest cavity, loops around the aorta and then back up to the larynx. This is the case for all mammals (imagine what a waste of resources this long and ridiculous route takes in a giraffe!). In our fish ancestors, however, the route is basically a straight shot. As the neck developed and the head moved away from the heart, this nerve could not simply be re-routed. Evolution is not capable of going back to the drawing board, only adding to what is already there. Amazing read, I highly recommend it.
One of the most interesting and revealing portions of this book shows the evolution of the laryngeal nerve. In humans, the laryngeal nerve takes a circuitous route, going from the brain, down into the chest cavity, loops around the aorta and then back up to the larynx. This is the case for all mammals (imagine what a waste of resources this long and ridiculous route takes in a giraffe!). In our fish ancestors, however, the route is basically a straight shot. As the neck developed and the head moved away from the heart, this nerve could not simply be re-routed. Evolution is not capable of going back to the drawing board, only adding to what is already there. Amazing read, I highly recommend it.
