YIF: Chapter 4 Review

February 3 2013, 4:56 PM  by Rinu Daniel

What significance do ancient teeth have to the overall story of life?

           Chapter 4 of Your Inner Fish by Neil Shubin talks about teeth and how they can tell us a lot about the animal they belonged to. They are especially important to evolution and finding our "inner fish" because they are the hardest parts of our body, even harder than bones, because of the enamel it is encased in. This means that teeth can be fossilized more easily, and therefore paleontologists find more teeth than anything else from hundreds of years ago. Shubin explained the different types of teeth and how you can differentiate the type of animal, it's diet, and whether or not it was a mammal. Shubin shared stories of his fossil hunting expeditions and also explained where exactly teeth came from and their importance. Teeth usually do not get as much praise as they need as most bones actually come from them and many do not realize how much an old tooth can tell us. The overall point of this chapter was to explain the importance of teeth to evolution. It helps explain the evolutionary history of the human body by how teeth started to adapt to specific needs and diets. For example, for humans, we have incisors, canines, pre-molars, and molars, each of them serving different purposes.

            The most interesting concept presented in this chapter for me was the fact that you can tell whether an animal was a mammal or not by their teeth. I had always known it was the hardest part of the body and therefore could be easily fossilized. I had also known that you can tell which kinds of animals the teeth belonged to and it's diets by the shapes of the teeth because every different type of tooth serves a special purpose. Being able to tell whether an animal was a mammal or not, however, was a very interesting fact to me because I had always known as mammals being animals who give birth through the womb, not born through eggs, and it seemed odd to think you can tell that from teeth. But from the way Shubin explained this concept, I understood it fully. I feel like this chapter relates most with Big Idea #1 because of the evolutional aspect of it. The chapter shows that your teeth continue to change and evolve due to your dietary habits, which is why most herbivores have more molar-like teeth and carnivores have sharper teeth.