Ch. 5

From the fingers of an ancient fish/amphibian, to the teeth of a rodent-like-creature, to now the head of a shark; it seems that we humans are nothing more but a mixture of ancient animal body parts, only modified. Anyways, chapter five shed a lot of light regarding our heads. Its amazing that in all the complexity that is our heads, only 12 cranial nerves are present controlling all the surrounding organs, as Francine said. Our ears, eyes, nose, mouth, and face is only controlled by a mere 12 nerves, while the rest of our body is controlled by thousands of other types of nerves. Even more, its interesting that the organs in our surrounding face is only controlled by a single nerve, yet it can perform so many functions with that one nerve.
When Shubin talks about how we as developing fetuses are only but four arches is truly shocking. In those four tiny arches hold the blue prints of our entire head, from the shape to the 12 cranial nerves, and shows how amazing our bodies are. These arches are vital for us to develop normally, and as shubin said, any defect in these arches with cause an alteration in the formation of our head. Once again, as some have mentioned, the diagrams and pictures, in this chapter especially, really helped me visualize and understand the concepts shubin was explaining. From the similarities of our crinal nerves to a sharks cranial nerves, to how our arches resemble ancient worm gills.
To me, each chapter has always surprised me about the origin of our organs. This chapter nonetheless has surprised me, telling me that the formation of my head may have the been the gills of some ancient worm. I wonder what other creatures may be the origin of our many organs in the upcoming chapters.