Fishy evolution

>>Neil Shubin’s Your Inner Fish documents
a remarkable discovery that could change
the way we understand and study our
bodies and minds

by Juliet Waters

Last November, when Oliver Sacks mentioned a book he was eagerly waiting to read, I made a few mistakes. I misunderstood the title and wrote it down as “You’re in a Fish.” Also, I misspelled the author’s name. When I hit on somebody who seemed like he might be the author, there wasn’t much on this guy, Neil Shubin, associate dean of medicine at the University of Chicago. He doesn’t even have a Wikipedia entry.

My other mistake was assuming that this would be another book about the brain. My vaguely imagined book was something about neuroconsciousness, seeing the world from the brain of a fish, with maybe a few interesting facts about autism and fish oil.

Google finally lead me to the actual book, Your Inner Fish: A Journey Into the 3.5-Billion-Year History of the Human Body. It turns out to be a remarkable book, though for none of the reasons I thought it would be.

First, because almost two years after having made an incredible scientific discovery, Shubin is little known. And second, because this book includes so little about the brain, which in this day and age of neurocentric science writing, is actually quite weird.

In March 2006, Shubin was part of a team of paleontologists who discovered a fossil in Nunavut that is likely the missing link between fish and reptiles. Tiktaalik looks something like a mer-reptile, with the tail and body of a fish, but two tiny arms that were probably not capable of much more than a few push-ups at the edge of a muddy stream.

Back when Charles Darwin speculated on the link between humans and primates in The Origin of Species, the world shunned, laughed at and eventually embraced him. Here’s how the world deals with the link between humans and fish: with relative indifference. And, judging by a few reviews, by wanting to know more about what this has to do with our brain.

Shubin, I’m sure, has many theories, but right now his mission as a gifted teacher and writer is to shift our obsessive fascination ever so slightly from our brains to our bodies, and in particular to our bones. Why? Because our brain evolved largely as an organ to manage our increasing collection of bones, and if we don’t have a thorough understanding of how these bones evolved, tapping the mysteries of the brain is all that much harder. As Shubin explains, it’s like being a mechanic trying to fix a souped-up Volkswagen Beetle. Many problems arise from the reality that the original vehicle may not have been built for speed.

Tiktaalik explains a lot of weird things that were previously unknown about our anatomy. Why, for instance a human embryo has ridges roughly like those on the body of a shark, and why predictable sets of nerves and bones spring from each of these ridges. The range of fascinating things Shubin explains about anatomy cannot possibly be summarized in this review.

Which is fine. It’s a book that deserves to be read as much as reviewed. What’s important to know about this book is that from beginning to end, it resonates the love of truth that led Shubin on several failed Arctic digs before he found his fossil. In an ideal world, this would immediately make him a bestselling adventure and science writer. In our world, right now, he isn’t.

It’s easy to see, however, why someone like Sacks would be so excited about this book. Medicine has always regarded the reptilian brain as the most primitive part of our own. If there’s a fish brain hidden somewhere in there, the mysteries of the brain may lie even deeper than we dared imagine. But will Shubin ever become as widely read and regarded as one of his biggest fans? Do fish walk? It’s been known to happen.

Your Inner Fish by Neil Shubin,
Pantheon, HC, 230PP, $28