"A jumble becomes part of a simple plan, and you feel you are seeing right through something to find its essence" (82). The cranial nerves that twisted toward difference muscles and sense organs gave Shubin (and me), the "willies". The human head seems like a "bewildering mess", but everything has its own purpose. The cranial nerves which "take tortuous paths through he head" and "exit the brain into a bewildering network of branches" interested me (83). I would like to see how my head looks like on the inside. It would probably be gross too, but how our brains(and everything else) is developed form "a big glob" is weird. Why do two different nerves, which innervate entirely different parts of the face and jaw, send branches to ear muscles that lie adjacent to one another?" (84). The analogy to the wires, cables, and pipes was helpful in understanding how complex it is inside our heads and how each thing has its own job.
Every time I read a chapter, Shubin teaches me something (which is everything) new. The shift of the topic from nerves to arches confused me a bit. But it’s cool how they develop jaws, ears, and our throats and how "children born with first arch syndrome have a tiny jaw and nonfunctioning ears with no malleus or incus bone"(89). Well, it’s not COOL, but it’s interesting :) And also how "children are born with an actual vestige of an ancient gill arch cartilage..."(91). Well, it is only physical similarities; our brains are much more complex than animals right? :)Shubin claims that "our head may look incredibly complicated...but it is from a simple and elegant blueprint" (93). I have a hard time believing this because this chapter was not...simple. Nevertheless, it was interesting.
Subscribe to:
Post Comments (Atom)
I agree- this chapter was fairly confusing in the beginning. Especially when he began describing the complicated paths of cranial nerves. However when Shubin related the structure of these nerves to the development within the archs, it suddenly made more sense. Grouping the development of tissues into compartments made a more complete- if not intriguing- visual picture of the development of the embryo. I was further enthralled with the idea that these archs are the same as what develops gills in sharks. I am continually amazed at how such a simple template creates every living creature, great or small. And while Shubin's expeditions don't exactly sound like Indiana Jones material, I can now more readily grasp his enthusiasm about discovering the path that led to man today.
ReplyDelete