Chapter 5 :Getting Ahead

The passage about the facial muscles intrigued me. I had never really thought about muscles in the face. The facial muscles didn't seem very significant and kind of surprised me that there were actual scientific names for them like the depressor arguli iris or the corrugator supercillii.
When Shubin started talking about arches, the chapter suddenly started to become perplexing and monotonous. However, when I read back so that I could have a better sense of understanding what the passage was saying, it became much more lucid.
I also thought the fact that humans and sharks have similar jaws was very interesting. It is hard to imagine that a 13 ton shark like the whale shark could ever have similar jaws to a much smaller human. However, it turns out that even though fully grown humans and sharks differ in many different ways, as embryos, they look very similar. The diagram on page 92 helped me to see how similarities between he structure of the cranium of a human and shark.
The most strangest thing that I learned in this chapter was the passage that stated that animals with heads are most closely related to worms with gill slits like the Amphioxus. They were "small worms that lack heads, complex brains, or cranial nerves. However, even though they seemed to differ from us by a huge amount, they were similar in the way they had gill arches. I couldn"t believe that the "essence of our head" could have came from worms that don't even have a head.