Your Inner Fish: A Journey into the 3.5-Billion-Year History of the Human Body

In Chapter 11, Shubin writes that there exists a “biological ‘law of everything’,” which states that every organism on Earth must descend from parents (231). Though this law seems obvious, Shubin argues that it is fundamental to understanding the history of the human body. How does this “law of everything” manifest throughout Your Inner Fish? Choose three different structures in the human body (eyes, teeth, ears, etc.) and discuss how the biological law of everything allows us to understand the structure’s development.

Shubin frequently argues that there exists an “inner fish” inside the human body. Explain what Shubin means by the concept of an “inner fish.” What are some of the ways that biologists like Shubin are able to see evidence of our fish ancestors?

Shubin’s evolutionary analysis depends on two distinct forms of biological evidence: fossils and DNA. Compare and contrast these two forms of evidence. What different stories does each form of evidence tell about the human body? In what ways is each better than the other for learning about our evolutionary development?

Shubin argues that the history of evolution is often one of repurposing, with evolution transforming existing organs and bones for new functions. Choose three different examples of evolutionary repurposing in the human body. How does repurposing manifest in each instance?

The theory of evolution, first outlined by Charles Darwin in his 1859 book On the Origin of Species, remains a controversial scientific theory. Some individuals reject evolution, instead subscribing to the theory of creationism, which argues that a divine being created all life on Earth. What is some of the evidence Shubin provides for the existence of evolution? How does this evidence support the idea that all animals evolved from a common ancestor?

Shubin writes that one of the defining traits of bodies is the division of labor, with distinct organs and body parts performing different functions in cooperation with each other. What are some of the earliest creatures to exhibit bodies with division of labor? How did these creatures develop from single-celled organisms?

In what ways are our bodies today limited by our evolutionary ancestors? How do we benefit from these ancestors? Are our evolutionary ancestral links advantageous or disadvantageous for us overall? 

In the first chapter, Shubin describes how paleontologists are able to predict which of the Earth’s geographic locations are most likely to have certain types of fossils. What are the methods that Shubin employs to perform his prediction? What scientific theories are these methods based upon?