YIF: Chapter 11

This chapter is the final chapter in the book Your Inner fish and is appropriately titled "Meaning of it all." In this chapter Shubin first tells us about evolution and how our genetic tree has developed over the past billion years. This is crucial for the rest of the chapter where he will talk about specifics that did not fit in the last 10 chapters. He relates our speech to that of primates and how they evolved together. Then talks briefly about how our fish and tadpole "ancestors" evolved and how we evolved from them and that is how we have hiccups. He explains that how hiccups are beneficial to fish in their breathing, whereas they are neither beneficial nor harmful for us humans. Lastly he talks about how our shark "ancestors" can help us, especially males, relate to getting hernias. The overall basis for these points in this chapter is the biological "law of everything" that states every living thing on the planet has had parents. The most important idea in the section was how we can link ourselves to each other and how all humans are related, no matter where from on earth, because we all evolved from a common point. The part I find intriguing is how we can tract this relationship with others. To do this we use a method similar to cladograms, except it is almost reversed. We look at a family tree of yourself and you can, for the most part, tell where another person that you have meet would fall. This process is much more complex than I gave it credit for, but that is essentially what happens. However this so called "family tree" would have to go back hundreds of generations of you, so it is not practical for the average person to do. This chapter reverts back only to the first Big Idea of biology that states: The process of evolution drives the diversity and unity of life. This is a very evolution heavy chapter and essentially this Big Idea relates to the chapter because Shubin keeps going back to the point that we have all descended from a common ancestor and thus these evolutionary links can be establish between us and other races. An essential question to take from this chapter would be: "How can characteristics from other species tell us more about our own bodies?"

YIF: Chapter 10

The chapter entitled "Ears" or chapter 10 is about the biology of the human ears and relating the middle ear and inner ear to biological ancestors. Shubin is quick to make the remark that the external ear that we humans have, is a trait that is unique to mammals although some amphibians and reptiles do have a somewhat external ear. The man component of the human ear that has been linked to other ancient organisms is the middle ear, composing of the stapes, malleus, and incus. These three ear bones have been linked to gill arches, the stapes in the second gill arch and the malleus and incus in the first gill arch. Through the brilliant minds of Karl Reichert, Ernst Gaupp, and W. K Gregory the link to fish as well as mammal-like reptiles has been discovered, because the three ear bones found in humans is strongly tied to the anatomy of these organisms. Next Shubin writes about the biology of the inner ear, a topic that fascinated me the most. He talked about how the ear works with the brain and the eyes to determine sound, position or acceleration. What was most fascinating was the part of the ear that is the main component in determining these three things. There is a gel like substance in the ear that is touched by hair cells. When one moves or shifts their body, the gel like substance shifts, and tiny rock like objects on top of this gel exaggerate the shift, causing hair cells to detect the movement and ultimately send signals to the brain. This chapter relates the most to Big Idea #3 and Big Idea #4. Big Idea #3 states Living systems store, retrieve, transmit, and respond to information essential to life processes. It is fairly obvious that the three parts of the ear, the inner, middle, and external ear all work to gather in order to obtain knowledge about the position of the person, their current velocity, and hearing sounds. Big Idea #4 states: Biological systems interact, and these systems and their interactions possess complex properties. And like mentioned before, not only does the three parts of the ear work together, but the ear as a whole works with the eye to get the most accurate information of the current environment that one is in. An essential question that can be formulated based on this chapter would be: How do ancient organisms with no ear at all come to evolve to create complex ear systems?

YIF: Chapter 9

This chapter called "Vision" is mainly about the biology of the eye and a little history of the eye. There are several fascinating experiments that scientists have done on eyes, but the evolution of the eye was not mentioned much. After all "[e]yes rarely make it into the fossil record." (Shubin 149) First the author talks about the biology of the human eye and talks about the molecules involved in light reception. Later he talks about these molecules being incorporated with tissues. Finally, Shubin went into detail of the genes in multiple eyeless genes, and showed how flies, mice, and humans have similar genes that turn on and off the eye genes. This last part was my favorite part of this chapter. Walter Gehring compared the genes of of flies, mice, and humans that all had a similar eye disorder. He found a similar gene in all three in of these organisms, and tested with the eyeless gene in flies and Pax 6 gene in mice and found that if he put the Pax 6 gene any where on a fly, an extra fly eye grew there. This showed the very close relationship between the eye genes found in these organisms. The only Big Idea in biology that relates to this chapter is Big Idea #3, which is  living systems store, retrieve, transmit, and respond to information essential to life processes. Brains respond to information that the eyes receive from their environment and transmit to the brain. The rods and cones are the main parts of the eye that pick up the light from the environment and the brain picks up these signals from various nerve cells. The brain then interprets the light information from the eye and acts accordingly. An essential question that can be made from this chapter is "How do we put variation to use in understanding how our ability to see developed over time?"

YIF: Chapter 8

This chapter titled "Making Scents" is, like the chapter suggests, about the nasal passage and smelling. Shubin spend time talking about the evolution of smelling and how this is relevant to the evolution of smelling to animals and even us humans. Shubin makes a remarkable statement that "our sense of smell allows us to discriminate among 5000 to 10,000 odors." It is very fascinating that out of all the molecules in the air we are able to pick out "up to one part per trillion." The connection to evolution is that "3% of our entire genome is Devoted to genes for detecting different odors." You can trace back to the genes for smelling out from the history of animals. This can be seen by looking at which genes are being expressed in fossils that are extinct or in animals that are still alive. What I found most interesting was how we smell. We smell by tiny molecules in the air which will actually attach themselves to neurons in our nasal passages. The complexity of these neurons is incredible. We have thousands of genes that express for the nerve cells that enable us to detect odors. And apparently we lost many of these genes throughout our evolution. According to Yoav Gilad "primates that develop color vision tend to have large numbers of knocked out smell genes." Going with the assumption in this book that we are we, as humans, are ancestors from primates, we can tell that we have lost large numbers of smell genes for our color vision. This chapter relates a lot to big idea one and four. For big idea one the process of evolution for smelling shows the diversity of life. As we saw in this chapter dolphins had blowholes and lampreys had a nostril and we, humans, have external and internal nostrils. As we look throughout our evolutionary history we see that the amount of genes for smelling has been increasing, this attributes to the diversity of life. For this chapter's connection to big idea for we see the molecular system of smelling and how our brain interacts with this. We see that small amounts of molecules enter through our nose and attach themselves to neurons and our Nasal passages. The book goes on about how the brain interprets these neurons and all of which is explained in great detail in this chapter. An essential question that can be made from this chapter would be, "How does an organism gain or lose the ability to smell?"

YIF: Chapter 7

            In this chapter of Your Inner Fish, the author does a lot of explaining about the history and organisms with different types of bodies, organs, and the way they make their bodies. The author explained about the collagens and other molecular chemicals that are found in bodies organisms, and how even some primitive organisms, like sponge, have these. The author did not say too much about this and its evolutionary connection with humans, but he did write about how the in the timeline of the Earth that there weren’t bodied organisms until about 1 billion years ago. He said that when bodied organisms started to appear on the Earth that the life that Earth had was forever changed. This explains why humans and animals of all kinds are bodies, which was the point of the entire chapter. My favorite part of the chapter was the short story about the evolutionary experiment that was performed by Martin Boraas. In this experiment he let single cell alga organisms thrive in a controlled environment. After 1000 generations, he let a single celled creature with a flagellum into the environment where it thrived off eating the other organisms. After less than 200 generations the alga organisms evolved into an eight celled ball where each of the cells could get light to photosynthesize, and where it wouldn’t get eaten by the predator. This is my favorite part because it describes an experiment that shows that evolution of an organism is very possible and it supports the author’s belief of evolution. The Big Ideas of biology that are connected to some ideas that are present in this chapter are:  living systems store, retrieve, transmit and respond to information essential to life processes, biological systems utilize free energy and molecular building blocks to grow, to reproduce and to maintain dynamic homeostasis, and the process of evolution drives the diversity and unity of life. The first Big Idea has connection to this chapter, and it is that when the author was talking about the timeline of the bodied organisms he mentioned that the organisms might have become bodied in response to predators eating them, also that the sponges respond to the outside environment with the information around them. The second Big Idea’s connection to this chapter is that the single celled biological systems utilized the energy from oxygen and the sun to become bodied and then the homeostasis of the prey was stabilized. Lastly the third Big Idea’s connection to this chapter is that all bodied organisms are diverse but at the same time united by the fact that they are multicellular and certain cells have certain roles, and also that all the bodied organisms are bodied due to the change in the way of life and body-building. An essential question that can be made from this chapter would be, “How (chemically) does one cell evolve to become an organism with two trillion cells?”

YIF: Chapter 6

            This Chapter does a lot of explaining of evolution in terms of embryos yet again. But instead of the connection between humans and other animals being gill arches it is about the body plan of the embryo in the very early stages of development. Karl Ernst von Baer did experiments with the embryos of chickens and other animals and noticed some very strong similarities. And his ultimate conclusion was this: “Every animal organ originated in one of [the] three [germ] layers. Significantly, the three layers formed the same structures in every species.” This discovery is found in humans as well, the three layers being the ectoderm, mesoderm, and endoderm. This shows that von Baer’s conclusion of the evolution is relevant to human evolution because since most animals have it, then it is likely that we descended from the same ancestors. When the book was talking about the human embryo stages of development was my favorite part of the chapter. I loved how it talked about the early timeline of the fetus in the mother’s body and how childbirth is such a wonderful thing. It was also very fascinating to know and understand what the fetus looks like before it has any distinguishing features. I think the most interesting part of this section of the chapter would be when the author talked about the three germ layers, the mesoderm, endoderm, and ectoderm and how they will all develop into separate organs, like the mesoderm into the body cavity and other organs and the endoderm into the digestive tract and other organs. The Big Idea that has connections to this chapter of the book is the process of evolution drives the diversity and unity of life, because the author lectures about the genetics and embryonic similarities between species so that he can convey that they are unified and also diversified. This is one specific example that was used in this chapter but there are many more connections that can be found as well. An essential question that can be made from this chapter would be “What can similarities in genetics cause to be similar between two creatures?”

YIF: Chapter 5

            This chapter was in some ways irrelevant to evolution. It took a little while for the author to tie what he was saying into the evolution of human. What he was mainly talking about was the head of mammals, fish, worms, and humans. What was special and what he said that they all have in common, yes even the headless worms, was that they all had something called the four gill arches. Each of the four categories of animals that I listed not long ago all have these arches and they look similar to each other when each of these animals is an embryo. It is when they develop further along into the stages of their embryo that they separate and look different from each other and each of the gills forms into something different. The author didn’t relate the four gill arches to the evolution of humans until he mentioned that the essence of our heads goes back to worms, such as the Amphioxus, who didn’t even have heads, and this is because these worms have the same gill arches, but when they develop they form separate organs that humans do and it is believed that these headless worms are part of the origin of the arches that we have. The most interesting part of this chapter was when the author said that “we can manipulate the identity of the gill arches almost at will, by changing of the gills inside.” (Shubin 94). This fascinated me more so than other parts of this chapter because it kind of reminded me of the ZPAs that we heard about a few chapters ago, in that we can manipulate the genes to change the embryo when it fully develops. In the book the author used the example of manipulating the gill arches of frogs by turning off some of the genes in the gill arches. The outcome of this was that the frog ended up with two jaws. That is simply interesting, however this does have much to do with evolution, and it only deals with the biology of embryos. This chapter has connections with two Big Ideas in biology, one being biological systems interacts, and these systems and their interactions possess complex properties, and the process of evolution drives the diversity and unity of life. The first idea makes a connection with this chapter because of the insane complexity of the four gill arches and how they develop into something so specialized and they interact with each other to make the organism better functioning. The second Big Idea makes a connection with this chapter because of the idea that the headless worms that existed millions of years ago share the same gill arches that several different animals, ranging from sharks to humans, have the same arches, but they develop into organs with different functions. This idea means that the diversity of the mammals can be unified by using the perspective of this one evolutionary aspect.