Chapter 3 Handy Genes

Randy Dahn's experiments in the beginning of the chapter really captured my attention and set the stage for what was to be introduced next. I was glad to see that Shubin decided to explain the actual process and procedure of his experiments in this chapter. It was interesting to learn that Shubin and his fellow scientists were able to manipulate the genes to get the results that they are looking for. For example, they were able to find the differences between fins and limbs simply by comparing the ensemble of genes that were active in the developments of humans and fish. Also, I was found myself interested at how Gasseling, Saunders, and Zwilling all received the same result from their experiments, and I was shocked when I read that vitamin A injected into a chicken embryo also created the same mirror-image duplication. The term ZPA that was introduced in this chapter stood out because I found it odd that this certain tissue could possibly control the formation of our fingers, making our thumbs different from our pinkies. In addition, I found it both weird and amusing that the scientists chose to give new genes names like Sonic Hedgehog. I would've expected them to come up with another complicated name like the fish mentioned in the previous chapter, but I liked that Shubin tried to humor his readeres from time to time. As I neared the end of the chapter, I was glad to see that Randy's experiments showed all appendages are built by similar kinds of genes. I learned not only more about our "inner fish" but also our connection to other living creatures, by the end of this chapter.