5. Getting Ahead

I agree with Shubin that the head is the most complex and confounding part of our body, but it was interesting to read about what goes on inside the tangled mess, like the four cranial nerves and how they act as cables. It's fascinating to learn how the head of an embryo does not form until several weeks later, which by then, is only a big glob and how such complicated body parts can originate from simply a ball of cells. The diagram on pg. 88 helped to elucidate Shubin's discussion on the four arch tissues that can be traced from an embryo to an adult and how the jaws, ears, larynx, and throat came about. After Shubin described humans as "modified sharks" and how we all have an inner shark inside of us, I realized that there is nothing humans do not have in common with if something as different as a shark and something as small as a worm have similarities with humans.