Chapter 4

This chapter was pretty interesting because I learned a lot about the history of teeth... Shubin basically told a story of the reasons why teeth and it's hard substance it is made of is important. Creatures used teeth as a weapon, but some were unique by using their teeth as a defensive. Then a cycle began of survival of the fittest... predators evolved their teeth into sharper ones, while the preys evolved their defense into a harder shell/skin. I look forward to reading the next chapter.