Chapter 6: The Best Laid (Body) Plans

This chapter continues to connect the embryo with tissues, genes, and DNA like the previous chapter. However, instead of the specific arches of the head, this chapter describes the source of the overall development of the entire body in an embryo: the three germ tissues. I found it incredible that our human bodies, something so complex, are developed from just three tissues that form our body. Shubin then goes on to describe the how these tissues that are unsurprisingly found in animals with bodies function through DNA and genes. Shubin refers back to the hox genes and attributes them to determining what is formed in our bodies (organs, bones, muscles, etc...) through the germ tissues. However, Shubin pointed out to me that these weren't the only genes in a body's development for a consort of genes such as the Noggin, BMP-4, and the Organizer work together and not separately to build different types of the body (such as when the BMP-4 turns off when the Noggin turns on). Thus far, this applied to animals with bodies like ours and Shubin finally applies our similarities to other types of creatures. Shubin concludes by revealing creatures like the sea anemone have primitive forms of Noggin. I felt this chapter was especially confusing with all the names, but overall, a great learning experience that seemed on topic.