Book Review: Your Inner Fish

          What makes us human? This question elicits answers on multiple levels. Some people frame their humanity in the context of religion. Others choose to frame their humanity in the context of their relationships with other humans. Neil Shubin, paleontologist and evolutionary biologist, chooses to frame this question in the context of evolutionary biology. In his book “Your Inner Fish”, he examines the commonalities found between humans and the entire spectrum of organisms found on earth, as well as offering a compelling portrait of a scientist at work. 
          Neil Shubin is famous for leading a paleontology expedition that discovered fossils of the Tiktaalik, which is a fishlike creature with a rudimentary wrist. The Tiktaalik, with its blend of fish and tetrapod features, is considered to be the missing link between sea creatures and land creatures. Part of this book is an accounting of the author’s expedition to the Arctic Islands where he discovered the Tiktaalik fossils. Regarding these expeditions, he says “Most people do not know that finding fossils is something we can often do with surprising precision and predictability. We work at home to maximize the chances of success in the field. Then we let luck take over.” As he shows, fossil-hunting expeditions are a combination of back-breaking work, educated guesses, and serendipity. The Tiktaalik, with its unique combination of fish and tetrapod features, is a glimpse at how sea creatures made the shift to land. This accounting alone makes his book a valuable treasure. However, Neil Shubin chose to delve further, by showing us the many commonalities that humans share with a wide spectrum of species. 
          Teeth showed up in the fossil record very early on; they were found attached to the impressions of soft-bodied jawless fish. As Shubin explains, the process by which teeth develop – the result of interactions between two different layers of tissue – has been adapted for the production of other organs, including hair follicles, feathers, and mammary glands. The author’s explanation for this startling array of adaptations is: “This example is akin to making a new factory or assembly process. Once plastic injection was invented, it was used in making everything from car parts to yo-yos.” In this vein, the author goes on to describe the evolutionary origins of our bodies, describing everything from the anatomy of our head to the development of our inner ear. 
          This is a book that offers a peek into what makes us human. More than that, this is a book that opens our eyes to the beauty of the world around us.