CHAPTERS 8-11

Chapter 8:
After reading chapter 8, I started to appreciate my olfactory senses more and stop taking them for granted. Shubin explained the process of smell by discussing that we perceive smell by inhaling odor molecules that then go to an area behind our nose where they are trapped by the mucous lining of our nasal passages. Deep within our noses is a lining of a patch of tissue that contains millions of nerves cells. The odor molecules then bind to this patch of tissue which then sends a signal to our brain which perceives these signals as smell. I was shocked to learn that there are so many mutations within our sense of smell that it knocked out many odor genes where we have multiple function less odor cells. Shubin really stunned me where he stated that we as humans traded in our sense of smell for our sense of sight. To think that we rely more on our eye sight that it started to 'deemphasized' our sense of smell that it created functionless odor cells.

Chapter 9:
Shubin used this chapter to reemphasize again the unifying theme that humans are a history of all types of animals through his explanations of vision. Shubin discussed that the shift from black and white vision to color ed vision can be traced back to the 'changes in the flora of the earth millions of years ago.' Shubin explained that colored vision can estimated to have been introduced about 55 million years ago, where before the forests had the same general color. But as time went on, the color started to diversify where more colors were introduced that forced mammals to have colored vision in order to survive. This chapter was able to show that vision is not only a necessity in every animals life, but that their natural surroundings was able to change and alter vision, and added color in order for animals to prolong their life.

Chapter 10:
The beginning of chapter 10 started off with the introduction of the three different parts of the ears: the outer, middle, and inner ear. Shubin went on to explain how the function of the ear goes about the enables each animal to hear. He was able to unify the similarities that each animals has to each other by discussing that the mammalian ear came about from the upper part of a fish jaw. The fish jaw started to shrink due to the transition from water residing animals to land walking animals. It was a very interesting to learn that parts of our ears hold the past of our transition from water to land. This fact really allowed me to see how truly connected we humans are to fish.

Chapter 11:
And finally to the last chapter. This final chapter was really the wrap to the overall theme of the connection between all different kinds of animals. Shubin begun the chapter by explaining the mechanics of genetics and also showing how specific traits are passed down from one generation to the next and how connected they all are. Shubin discussed different traits that humans acquire through their past history by explaining the difficulties humans are forced to undergo because of their past. Humans for example weren't made to be inactive and have a hard time today due to the lack of activity. In previous times humans were used going through long periods of times without food, and end up storing the fat for later. But now with different times, and fast food everywhere, humans now face different diseases such as obesity and heart attacks.