Your Inner Fish- Week 2

By reading the first pages of Your Inner Fish I am able to say that this book is very interesting so far! I liked Shubin's statement of how "every rock sitting on the ground has a story to tell: the story of what that rock looked like as that particular rock formed." He then transitions into dedicating most of the chapter to the actual discovery of the Tiktaalik. He finds this fossil in order to determine the origin of limbed animals.

I thought it was very intriguing when he mentioned that only 99% of all species that ever existed are actually extinct. In the beginning of the first chapter he questions the reader by asking “How can we visualize events that happened millions and, in many cases, billions of years ago?” He answers this question throughout the whole chapter by talking more about the fossil record and its relevance in determining evolutionary similarities and differences between certain organisms. He describes his journey in discovering the Tiktaalik fish. I thought it was fascinating how the fossil of Tikataalik confirmed a major concept of paleontology in that it showed characteristics that aquatic animals, like those of fish, and land animals, such as amphibians both shared. The Tiktaalik demonstrated the evolutionary transition between terrestrial and aquatic life. He also spends time in describing the many anatomical features that the Tiktaalik presented that were structurally homologous to those of humans but not fish. For example, the Tiktaalik have a neck that is able to operate independently from its entire body, similar to all terrestrial vertebrates, including humans. Yet, this is a structure that is not familiar in fish. By discovering this fossil, Shubin is able to show that particular features in the anatomy of Tikaalik and humans are in fact very similar. By showing this similarity, he introduces the concept of “the inner fish.” I think that this was a great introduction to the book and I am really excited to continue reading more!