Chapter 8-11

Chapter 8: Just like previous chapters, Shubin enabled the readers to grasp and anticipate what the following chapter would entail. Though the process of smelling seems complicated, it was easy to apprehend through analogies he provided such as the lock-and-mechanism and a chord. Similar to that of a chord, I've learned an odor is the product of signals from receptors keyed to different odor molecules. Also, it was interesting to discover the main difference from humans and lampreys for they extract odors from water instead of air. I finally knew why dogs are used as trackers: they have several genes devoted to smelling meaning they are more sharp to differentiate smells. On top of this, I was fascinated how nasal genes in dolphins and whales had been modified to be used for breathing rather than smelling.

Chapter 9: I've wondered how paleontologists were able to explain evolution involving vision since there aren't as much fossils record as bones. As I read on, I figured it was possible. I merely thought we use our eyes for sight; however, that wasn't the case because they need to capture light for the brain to process an image. Never would I learn how complex our eye process was if it wasn't for this book. It takes numerous steps, for instance, a light needs to pass through the cornea then through the lens which later engage in light receptors and so on. While reading, I thought to myself, 'Just like the dog with extra nasal genes, if a specie had more "ocular genes" would it have better vision than others?' I was unexpectedly absorbed with this chapter as Shubin mentioned a real life situation that occurs almost every night when I am about to sleep. I eventually discovered why it was impossible to see anything when I went from a bright place into my dark room--- the light gathering molecules need time to recharge. It was a bit nightmarish towards the end when Walter Gehring turned on the eyeless gene on a body and an eye had developed there.

Chapter10: Again, I never expected to discover so many things through this book. Who knew we had three parts to our ear when we all we can see is the external part? From Shubin, I realized there is actually three which includes the middle and inner as well. I was surprised myself when I read "It surprises most people to learn that some of the most distinctive traits of mammals lie inside the ear." It is known that mammalian middle ear are different from other animal for they have three bones whereas reptiles and amphibians have only one. It was astonishing to learn Reichert's proposal that parts of the ears of mammals are the same thing as parts of the jaws of reptiles and Gaup's work that the two other middle ear (malleus and incus) evolved from bones set in the back of the reptilian jaw. Their notion seemed hard to believe since the tie between reptiles and mammals were subtle. It was more surprising when Shubin noted that a bone inside a human's ear is the same thing as the rod in the upper jaw of a fish, which ultimately shows that humans evolved from a fish. To me, this chapter stood out the most as it contained an experiment for readers to attempt: "..move your head back and forth while looking at the page. Keep your eyes fixed in one place as you move your head."

Chapter 11: After reading the very last chapter, I truly became fond of Shubin and his work. I was able to gain a profound insight in evolution in which humans and living creature share several common traits. For once I wasn't as shocked as before when there was a list of features we shared with animals including polar bears, turtle, fish, WORM, and jellyfish. I learned just as peeling an onion, we expose layer after layer of history as we see features we share with mammals and by looking deeper, with fish. Most importantly, I obtained a life lesson that if we want to avoid heart disease, diabetes, obesity, and stroke, we should apportion our meals according to our daily activities and move more often to pump the blood up the veins. It was terrifying to learn that with lack of exercise in the legs, problems can develop causing blood pools in the veins. Never did I know choking was harmful until now for food can get lodged in the trachea through which we breathe. Nonetheless, I was intrigued to discover that hic, hiccup is an outcome of the history we share with tadpoles and I liked how Shubin threw in a fun fact that the longest hiccups lasted from 1922 to 1990.

:)