Smell has always been mysterious to me. I never put thought into smell and how it effects our survival or our body's processes. This particular chapter was interesting, because it helped open my eyes to what smell does do for our body. I never thought of smell as something that could be composed of molecules and as a physical object, rather than an abstract idea. The origin of our nose, or nasal openings, was also fascinating. I had also not put much thought into how we, as humans, developed our sense of smell from primitive forms in the past. Smell has been present in Tiktaalik, and their nasal passages were developed like ours. This shows the evolutionary connection we share with Tiktaalik through the sense of smell.
Chapter 9: Vision
Vision is important. Animals utilize everyday, and it seems to be the most important sense we use today for survival. Looking back at the past, it is important to notice the complex development of the eye into the organ we use today. Simple eyes, such as those in lampets and nautiluses, don't have all the complex features that human eyes do. The further complex an eye is, the more acute the vision. I found it fascinating, and wondered what it would be like to have a simpler eye. Also, it was simple to see a connection we have to apes with color vision. It is fascinating that only primates have more than two kinds of receptors which enable us to distinguish far more colors. It set me on a train of thought, and let me wonder where evolution will take the eye next.
Chapter 10: Ears
The ears are magnificently complex structures that I normally don't give much thought to. However, the chapter helped give me new ideas about the ears. I was unaware that the inner ear, which controls the nerve impulses to the brain, was the most ancient part of our modern ear. If I was not to think about it, I would say the outer ear was the most ancient, because it seems the most primitive. I then realized that the inner ear had to be as it was the only part with a direct connection to the brain. The diagrams in the chapter help me trace back the heritage of the ear and its origins, including which specific parts of ancient species it came from. One strange part of the ear I never knew before was the addition of liquid inside of it. Now that I go back and give it thought, it explains so much about how our brain operates whenever it is disoriented. It explains why moving quickly and rapidly (i.e., getting out of bed too quick) causes the brain to become confused.
Chapter 11: The Meaning of It All
The book was interesting, and the last chapter certainly tops it all off. Shubin's reflections on the way these genes spread throughout history were especially helpful. The two family trees, of the family of clowns and of the normal animals, helps further explain everything up to this point. All of these parts of the human body, from the bones to the complex senses, have all originated from a single common ancestor at some point that decidedly got more complex as time went on. A more sobering point is one that Shubin makes mid-chapter, as he explains that we are not genetic masterpieces. Shubin helps me understand that the complex path our bodies have gone through have left us with a multitude of problems, like cancers and tumors. Our common animalian history, too, has also left us unprepared for the inactivity present in modern society. Altogether, the book has left me interested in biology, and reminded me of what I should have never forgotten. Through Shubin's voice, I have learned a small section of the story of the human body and have found myself thirsting for more.
No comments:
Post a Comment