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

As interesting and informative as other reviewers have promised it to be.
If one is a Creationist however, you will not like this book.

If you are interested in a good, nontechnical book on how much our body design owes to our evolutionary past, this book could be for you. Shubin is an excellent writer. There is not a boring page in the book. He has a real knack for making complex ideas understandable without talking down to the reader. This is lost on a few reviewers who seem to mistake clarity for lack of depth. If this book turns some readers on to investigate science more deeply, that will be a great thing.

In particular, his account of the evolution of wrists, ears, eyes, and even animal bodies themselves, as evidenced by both fossil evidence and DNA similarities makes it clear that if a "Designer" were responsible for all this, "he" would be more of a tinkerer, making use of old parts and forcing them to do new things. Naturally these changes took millions of years to happen, being the slow result of tiny mutations in each generation of life. This is the thing that is so hard to comprehend for most who doubt this explanation for life's diversity. One can't directly comprehend two billion years of life's evolution. But science shows us that its record is written in our bodies themselves. We all carry this record, and we should be proud that we've made it this far.

I had to get this book for a class. I wasn't really looking forward to reading it to be honest and it turned out to be quite a surprise. I absolutely enjoyed it and I'd recommend it to anyone interested in this subject.

I think this book would be a decent read for someone with minimal science literacy, but really it is pretty elementary stuff. I kept wanting more technical details and I felt the author breezed through the subject matter in a fairly superficial way.
If you are already even remotely familiar with evolutionary biology then this book might be a little boring. I would, however, recommend it for those who are just being introduced to this subject - perhaps seventh graders?

It does not take a trained eye to see that there are basic similarities between animals -- this is, after all what allows humans to "play" horses and dragons and cats with just a wee bit of makeup and costuming. Most mammals, birds, lizards, fish and even insects have a head, a body and various appendages stick out for locomotion, manipulation and catching prey. But are these similarities just apparent, or do they go deeper?

Biologist Neil Shubin documents the fascinating truth that human beings (and birds, bees, etc.) share fundamental body patterns with each other. And that these patterns are well-nigh ubiquitous. Shubin examines the common animal limb pattern: one upper bone, connected to two lower bones, connected to blobs of wrist bones, connected to a number of elongated digits. To make a bat wing, lengthen the digits and cover them with skin. To make a horse hoof, elongate the middle finger and fused the others into a solid mass. But our similarities go much deeper, and Shubin provides a fascinating tour through the world of embryology. It's here that scientists have discovered, by painstaking trial and error, the chemical messengers that form our bodies from formless blobs of cells. He discusses the Hox gene (found in humans, mice, fruit lies and much animal life) that programs an embryo's head-to-tail features. He shows how distance from ZPA (a patch of organizing tissue) determines the length of fingers, turning some into pinkies and some into thumbs.

The book is interesting, often exhilarating, and hard to put down. What's neat is the glimpse we get into the toilsome work of the scientists who collect, prepare and analyze fossils. It takes years of work, sharp eyes, luck and a knack for puzzle solving to piece together, say, the story of how mammals developed precise chewing - an ability that reptiles do not have. A tiny tooth found on a beach in Nova Scotia can fill in the gaps of how and when the transition from reptile-style toothedness and mammal-style dentition came about.

I had only two criticisms. Unlike Stephen Jay Gould, who tends to write far above the heads of intelligent readers, Shubin tends to write down a bit. Unlike Gould, Shubin avoids scientific jargon, to a degree that is curious. Secondly, he leaves some rather large gaps in his tale. While it is interesting that animals tend to have the same skeletal limb structure, why did they adopt this structure? Is the one bone/two bone/blobs/digits model the only one that works out of water? And why/how did the creatures begin to move in the direction of limbedness? In the ongoing debate between evolution and creationism, such insights would have helped answer the nagging questions that even proponents of evolution have about the mechanisms behind it.

Still, "Your Inner Fish" is an accessible and informative read about the personal process of collecting bones and the intriguing conclusions that science has made about our relationship with all (and I mean all!) animal life. The next time you listen to the radio, thank the ancient fish whose jawbones evolved into the bones of your ears. And give a thought to box jellies, with whom we share the basic mechanisms of sight.