Chapter 6: The Best-Laid (Body) Plans

When the chapter started out with the discussion of comparing primitive animals such as jellyfish to human structures, I did not think Shubin would make a bridge or transition with all of the discussions of embryos, tissues, hox genes to his final point. Moreover, with all the talks about embryos and DNA from previous chapter, I was concerned on how to digest more information of the same subjects without confusion. However, unlike from last chapter, Shubin started off easily with common knowledge of steps to the development of animals that would be taught in a biology class. As I read through the pages, I was shocked how origins of embryos consisted of same materials such as three tissues. Then, Shubin explained how germ layers such as mesoderm and ectoderm play significant roles in forming organs, bones, and etc. As the subject got deeper, he demonstrated how genes such as Noggin, Organizer, and BMP-4 function accordingly to build different types of bodies. With all these information condensed, the chapter ends with how traits found among unlikely compared animals are from same origins. For example, although Shubin described comparing the primitive creatures to human was psychiatric to strengthen the degree of the topic, he made the topic look easy through specific examples and analysis to make the comparisons pragmatic.