Chapter Six: The Best-Laid (Body) Plans

One part that caught my attention was when Shubin explained that almost all animals, including human, share"von Baer's three germ layer" structure: The ectoderm, the endoderm, and the mesoderm. These important layers form many of the inner structures of our body, such as the digestive organs, skeletons, and muscles. Another interesting part was the comparison of flies and humans,"versions of hox genes appear in every animal with a body. The eight genes which contain the homobox, responsible for genetic mutations, hox genes are found in many creatures, in different numbers." The only difference, in Shubin's opinion, between flies and men is that flies have one set of eight hox genes while humans have four sets of hox genes.

Shubin's comparison between humans and creatures such as fish, amphibians, and flies, was surprising enough; Shubin introduced a new comparison, between human and jellyfish. I was shocked when i read about the author's experiment of the gene, noggins. "Take the product of noggin from a sea anemone and inject it into a frog embryo. The result: a frog with extra back structures, almost the same result as if the frog were injected with its own noggin." (124). This chapter was full of strange comparisons between humans and unexpected animals, but i learned a lot about common inner structures of many creatures.