chapters one, two, and three

first off, sorry for the delay in chapters because I didn't get the invite... well, anyways

When I first started reading this book, I was interested in the idea of evolving from fish because I have only heard of evolving from apes or other primitive forms of primates. Then after reading several pages of this book I saw that coming from fish made sense since the earth consists mostly of water and that the animals just needed to adapt to the surroundings especially when they began to step on the land. When the author states, "We can then use the features common to all species to identify groups of creatures with similar traits... when we do this, we discover something very fundamental about nature" (7). This reminded me about vestigial structures in animals as a part of developing our own anatomy as "advanced," at least compared to that of the fossils, and that it ties in with the concept of "how creatures are related to one another" (8).

This idea from chapter one is exemplified in chapter two as well, as Sir Richard Owen observed the "important patterns in the seeming chaos of life's diversity... our hands and feet, fit into a larger scheme. All creatures with limbs have a common design" (30). The connection between our anatomical organization and that of other animals really shows Shubin's idea that creatures really are related since we all have the same "underlying blueprint" (31) that makesup our bodies despite differences in species "frogs, bats, humans, and lizards are all just variations on a theme" (32). Also in chapter two, I found it interesting how the scientists were able to figure out and interpret how the Tiktaalik could do push-ups and its reasons for doing so. It again shows development in our structure and provides us with the origins of pronation and supination that, thanks to Tiktaalik, we now have. I also like how Shubin emphasizes the fact that " we are not separate from the rest of the living world; we are a part of it down to our bones..." (43). Despite our difference in intelligence, expression, and behavior, humans are actually not much different from other animals because, as evidence shows, we simply come from the same origins and there has always been a connection between humanity and wild animals written in our very bones and genes.

Chapter three first describes Shubin's lab and he enlightens the fact that although fossils may contain information about the beginnings of animals, there is a limitation with working with them. I found this to be very true and in his description of his lab, "half devoted to fossils and the other half devoted to embryos and DNA... Experiments are great because we can actually manipulate something to see the results" (45) I thought it reflected some kind of aspect in the whole scientific method idea - that a scientist cannot expect to find the whole entire truth if he only works with just one part of it. It leads scientists to reach out to different branches of science from paleontology to anatomy to genealogy in order to find the answers to some of the most asked scientific questions of all time. Also in studying and experimenting with the genes they will be able to connect the genetic switches that may have changed during the origins of the limbs and led to the formation and distinction of the different parts of the body. The experiments with the vitamin A and others show that there are no limitations to what science can do, attain, and discover.
This chapter was also very informative about the ZPA. Although some parts were a bit difficult to follow, I liked how Shubin posed some questions that sort of guided the reading and connected the animal findings to the way human bodies work as well. I knew that DNA contained the information to build the body, but I never realized how much of a difference such a small thing could make - that this tiny patch of tissue is responsible for the significant distinction between fingers. Thanks to ZPA we could give a thumbs-up to finding an inner fish, fly, or chicken!

Alexis Jacalne