Chapter 4 - Teeth Go 'nom nom nom'

I liked the introduction to this chapter. It slowly gave a transition from the technicalities of DNA to the function of teeth. I also found it interesting how much scientists can discover about an animal based on its teeth, or the way it chews. Teeth also contain a high level of hydroxyapatite, which makes teeth harder than bones and easily preserved.

Before, I had always thought that looking for bones -- and now teeth -- needed more of luck than anything else. However, Shubin's friend Chuck proved me wrong when he proved that he was looking for " 'something different,' something that had the texture of bone not rock, something that glistened like teeth, something that looked like an arm bone, not a piece of sandstone" (Shubin 64). Shubin simply proved his point the first day that he found a tooth -- every day thereafter, he was able to spot fossils very easily. They finally found the jaw of the tritheledont, which they said to be part mammal, part reptile.

Later, Shubin's expedition group proved that serendipity is once again needed to find what they are looking for. While they were accidentally stuck on a cliff because they lost track of time, they find countless pieces of bones that help in their quest to uncover lost mysteries.

Towards the end of the chapter, the diagram that branches from skin to hair to feather to breast to tooth etc. was really helpful in visualizing what Shubin's ideas are turning out to be. The last paragraph where he roughly summarized what the last four chapters have been about were really helpful for recall as well.

~Megan Hsiao