Ch5. Getting Ahead

In my opinion, I think this chapter is probably the best out of what I have read so far. I didn't realize how complex our head was until Shubin described the overlapping nerves, but then when Shubin traces the development of these nerves to embryos, everything makes sense. At first I didn't understand what Shubin was leading at, but the diagrams Shubin used comparing the Archs of an embryo and a grown adult helped me understand. I also liked how Shubin used a pretty good analogy leading up to the discussion of embryos, "If you want to understand the wiring and plumbing in my building, you have to understand its history, how it was renovated for each new generation of scientists, My head has a long history also, and that history explains complicated... For us, that history beings with a fertilized egg," (86).

Yet again, Shubin finds another relation to us to sharks, that being the formation of archs in our heads. It was hard for me to imagination that the basic structure of my head and the sharks are the same, even though we look totally different. I was amused about the picture comparing the human embryo and the shark embryo because both looked so similar. Shubin even relates us further back to worms, where even animals without heads at all have similarities to us. Although the appearance of hour head internally changes as evolution occurs, the basic structure remains intact.