Chapter 6: The Best-Laid (Body) Plans

I really was amazed by this chapter because this one explained how embryos of different creatures are all similar during the beginning stage. I never thought that a human embryo would look similar to that of a chicken. As Shubin explains in page 99, all organs in the chicken can be traced to one of three layers of tissue in the developing embryo called the germ layers. Knowing that these layers form all the parts of the body was very interesting, not to mention that this applies to humans also. Furthermore, the similarity of these germ layers in all fish, reptile, and mammal was even more shocking, learning how every heart of every species formed from the same layer. And also the brain from same layer. Moreover, the diagram in page 103 really amazed me, learning that this picture represents us humans during our primitive form. The formation of tube within a tube along with the three germ layers were bit confusing to understand at first but as the chapter went along, I began to understand the concept behind it. Overall, this chapter was very intriguing, learning of another similarity that humans share with other species.