Chapter Three: Handy Genes

Overall, Chapter 3 has been by far my favorite chapter, but also the most confusing. Throughout the chapter I found myself re-reading the sentences multiple times to fully understand and capture what Shubin was trying to say. However, re-reading and making sure that I understood the message was what made the chapter my favorite so far.

One of the most interesting concepts of this chapter was learning about the ZPA. For starters, I had no idea what a ZPA was but I was taught how much our body depends on the small patch of tissue after reading about the experiment with the foil. In this way, I thought that Shubin did a great job in this chapter as well as previous chapters in engaging the reader to a topic by making easy to understand relations, such as the foil experiment. Knowing what the ZPA was made it easier to understand the discovery of ZPA from chickens and the Sonic Hedgehog genes from fruit flies. Shubin made it clear to the readers that there is a connection between almost all animals and how they can all benefit from each other. Prior to reading this chapter, I had no idea what the Sonic Hedgehog gene was, and how so many different animals share this gene. The experiments that scientists make on animals and insects such as chickens and flies make it possible for them to find further information that connects all of us together. Also, once again Shubin adds diagram to his writing such as the image of adding extra ZPA to the wing bud of a chicken. This helped me picture the idea of a deformity of an animal, which was beneficial in understanding the process of the ZPA. However, this chapter seemed to have less pictures and diagrams as opposed to previous chapters, making it at times difficult to picture the information that Shubin conveys.

All in all, both ideas of the ZPA and Sonic hedgehog in Chapter 3 allowed me to understand the connections that all living creatures have. No matter how physically different we may seem, there is something that connects us all together in some way. Still, it is so bizarre to imagine my distant ancestors to have been a fish, but hopefully reading on will help me to understand and grasp the concept easier.