Your Inner Fish

I recently read a book by Neil Shubin called "Your Inner Fish", which is a wonderfully written treatise on the evolution of our body and how we owe many of our features (and problems) to fish, tadpoles, and other distantly related organisms. The book contains many interesting tidbits, such as the idea that hiccups are probably a relic of the reflexive breathing method used by tadpoles - a short breath in, followed by a closing of the glottis (flap of tissue that covers the windpipe). Stupid tadpoles.

I bring this up because I casually tossed the phrase "inner fish" into discussion the other day while talking about mammal evolution in my freshman biology class and it generated quite the response. Many students had never heard that we had had fish parts in us and were fascinated by the idea. We don't really have fish parts in us, but we do have parts that evolved from various fish structures. For example, your inner ear bones which allow you to hear such a wide range of sounds are modifications of the gill arches of bony fish. Some of the students had heard vague stories about how humans might have evolved from monkeys or something, which while technically incorrect (we evolved from apes), is still more than most knew. But the juxtaposition of the words "fish" and "you" seemed to do what other methods of teaching evolution had failed to do, namely elicit an interested response complete with a battery of questions and interesting discussion. At the end of the process, most were asking questions beginning with "so when we were fish..." or "so when our ancestors were reptiles..." rather than questions that begin with "My pastor says...". It was a great experience, and I think I'll probably throw that phrase around a little more often in class from now on.