Chapter 3

This chapter was not very interesting comparing to chapter1 and 2. I sort of had a hard time on focusing in this chapter, because I had a hard time understanding about the ZPA and DNA changing the skates, chickens, flies, and sharks into a sonic hedgehog feature. Even if it was boring, I have learned a lot of things. I have learned that these experiments with finding the inner:chicken, fly, and skate helped us learn more about human birth defects. Who knew that changing just a millimeter of tissue from the embryo can change the birth of an animal.