Getting Ahead (Ch. 5)

After reading chapter five, I found it quite interesting how Shubin stated, "Twelve nerves supply these muscles, each exiting the brain to travel to a different region in our head," (pg 83.). Although the cranial nerve actually has only a single function, that function serves to allow humans to do many important things, such as seeing and hearing. The true complexity of humans' inner bodies is shown when Shubin mentions the major roles of the trigeminal branches. Knowing that the trigeminal's branches control muscles and also carry sensory information from the face to the brain, just imagine what would happen if the trigeminal branches didn't properly do its job.
When Shubin also describes how the embryos of humans and those of sharks have conspicuous similarities, it amazes me how such similar embryos can turn out to become very different from one another. Furthermore, when Shubin included, "... we can manipulate the identity of the gill arches almost at will, by changing the activity of the genes inside," (94), I became aware of how far humans have come, in terms of understanding the inner structure(s) of both humans and other living organisms.