Sunday, March 24, 2013

YIF: Chapter 11 Review

What is the whole point?

Chapter 11 of Your Inner Fish by Neil Shubin is the last chapter of the book. In this chapter, the author basically summarizes the whole book with that everything has parents. From us humans now to the small chemical bonds millions of years ago, though it may not be the same concept of a "parent", they all still had them. Nothing on this Earth just randomly appeared out of nowhere, everything evolved to what it is and will be. I thought in all it was a good way to end the book.

The most interesting part of this chapter I thought was the part where he explained hiccups and how they are actually part of our ancestry with fish. Even throughout this whole book, and years of learning about evolution in schools, its still hard for me to wrap my head around how something like a small fish in my aquarium slowly mutated and evolved so much overtime to basically become me. The information about hiccups just brings it all together, kind of pushing us back to reality from this space of genes and DNA and scientific names. This chapter connected most to Big Idea #1 definitely because it completely talks about evolution, summarizing the whole book. In all I really enjoyed it.

Sunday, March 17, 2013

YIF: Chapter 10 Review

How does the human ear provide information about our evolutionary history?

In Chapter 10 of Your Inner Fish by Neil Shubin, the author moves on from eyes to ears. The ear itself is a complex system and a couple decades before Darwin, another scientist discovered that the bones of the inner ear are very similar, if not the same, as the ones found in the jaw of reptiles. As the information is believable now, it wasn't back then especially without the introduction of evolution. But when embryos are studied throughout their different stages, it is shown that the slits in an embryo that form gills in a fish, specifically a shark, become the bones inside of an ear of a human being. The chapter also explained interesting information about the connection between the ear and how one keeps balance.

The most interesting part of this chapter was the section that discussed why one starts to stagger after getting drunk. I knew it happened, but I never knew the scientific reasoning behind it. It is because the alcohol from the bloodstream replaces the fluid in the inner ear, causing the brain to think that their is movement, when there really isn't. It's why you would feel dizzy. This chapter most closely relates to Big Idea #1 because it talks about the evolutionary history between fish and human beings.

Sunday, March 10, 2013

YIF: Chapter 9 Review

Why is eyesight such a key and simple, yet diverse, feature on animals?

     Chapter 9 of Your Inner Fish by Neil Shubin moves onto another key feature of the face, from the nose to the eye. The eye has always been a organ of wonders, the way we see things and how different animals do not see colors as clearly as us humans. The way the human eye worked had been long discovered and understood by scientists and researchers, the way it reacts and absorbs light to give us sight. Though all organisms have a light absorbing molecule called opsins, only a few organisms, the ones closely related to human beings, have the three genes for color vision, required for seeing a large range of color.

     The most interesting part of this chapter was that eyes have a gene that can be turned on and off. Scientists took this gene in fruit flies and moved it around to different spots of the body, and saw that when the gene was turned on in that specific place, an eye would grow. I found that to be really cool, but quite creepy when actually thinking about it. This chapter is mostly related to Big Idea #1 because it talks about evolution and how the worm found in 2001 had the vision system of both invertebrates and vertebrates.

Saturday, March 9, 2013

YIF: Chapter 8 Review



How can our senses of smell lead to understanding our evolutionary history better?
Chapter 8 of Your Inner Fish by Neil Shubin begins the discussions of the senses. This chapter is about the sense of smell. The sense of smell, as many don't know, can provide great knowledge about the history of mankind. Our genome has 3% of its genes dedicated to the sense of smell. This is connected to evolution because we cannot detect many scents anymore because many of the genes for those have stopped working due to mutations. This didn't only happen in humans though, it's happened in similar animals too, due to the same mutations. This shows a clear connection.

            The most interesting part of this chapter was that something as small as the sense of smell can constitute a part of the large story of life. I would've never have thought that something like the sense of smell could tell you about evolution. This chapter most closely related to Big Idea #1 because it  talks about the evolution of animals. An example is of how the human sense of smell has lost a few scents, but so have other similar animals, showing we might've come from the same ancestor. 

YIF: Chapter 7 Review


What was our true ancestor?

            Chapter 7 of Your Inner Fish by Neil Shubin talks about the process of single celled organisms to multi-cellular organisms like us humans. As the chapters go along they are progressively getting more and more complicated and complex. Science shows that we all had one common ancestor that, way back in ancient history, was a single celled organism. Most of Earth's history was made up of single-celled organisms. Over time though, through evolutionary processes, bodies started to form, multi-cellular bodies. Today, if a cell is taken out of our bodies (depending on which cells) our life could quite possibly be at stake. In multi-cellular processes, the cells do not act alone anymore but instead rely on each other to survive. In single celled organisms, this was not the case.

            The most interesting part of this chapter was that multi-cellular bodies first appeared, at least in fossil records, a little more than 500 million years ago. This was especially interesting to me because  that, in the scope of Earth's history, is not very long at all and to think that it only took 500 million years to have a single-celled organism to become what we are now is amazing and hard to wrap my mind around. This chapter, like many of the other chapters in this book, relates most closely to Big Idea #1 because it has to do with evolutionary aspects and talks about the growth and process of a single celled organism becoming a multi-celled organism over time. 

YIF: Chapter 6 Review



How are the layouts of our bodies related to different animals'?

            Chapter 6 of Your Inner Fish by Neil Shubin is about the layout of the body. He talked about how all tetrapods have one head, four limbs, and a tail. This chapter mainly talks about how specifically a group of cells can become complex organisms such as humans or birds. It explains how the cells will first form a tunnel sort, with buds representing different parts of the body. This part seemed similar between different animal's embryos. He then talked about the next developing stages of the body and about different experiments that scientists did on embryos to fully understand why our body's layout is the way it is.

            The most interesting part of this chapter was that the same parts of the cell layer form the same body parts in every animal. That was very interesting to me because of the uniformity, even when species can be so different. It shows that we all had one ancestor. This chapter connected most to Big Idea #1 because it talked about evolution and the chapters information gives even more evidence to the theory that we all came from one common ancestor. All tetrapods sharing the physical characteristics of having 4 limbs, one head, and one tail is also a clue. 

YIF: Chapter 5 Review



How can the shapes of our heads tell us what other animals we are like?

            Chapter 5 of Your Inner Fish by Neil Shubin is about heads and their relation to evolution and what they can tell us about our "inner fish". He goes on to explain the anatomy of the head, how it is made up of different parts, plates, blocks, and rods. From explaining these parts, Shubin transitioned to talking about embryos and how, interestingly, the parts of the embryo that form a human head are the same of those of a shark and really any other vertebrate animal, composed of 4 arches. Shubin explained what each of the arches are for, what parts of the body they would soon develop to be. This chapter helps explain the evolutionary history of the human body by showing the fact that all vertebrate animals share the same 4 arches in the embryo, a clear sign that we all have the same ancestor.

            I thought the most interesting part of this chapter was that the parts of the embryo that form a human head are the same of those of a shark. I never would've expected this due to the large physical differences between sharks and human beings, from the surface it seems that we don't have practically anything in common. But I know from reading this book that we actually share a lot more than apparent. It is very significant that it happens to be a shark that the embryo looks like as we are on a quest to find our "inner fish". This chapter relates to Big Idea #1 because it is completely talking about evolutionary history and gives evidence to how we all must've come from the same ancestor by giving examples of the embryo head. 

YIF: Chapter 4 Review




What significance do ancient teeth have to the overall story of life?


           Chapter 4 of Your Inner Fish by Neil Shubin talks about teeth and how they can tell us a lot about the animal they belonged to. They are especially important to evolution and finding our "inner fish" because they are the hardest parts of our body, even harder than bones, because of the enamel it is encased in. This means that teeth can be fossilized more easily, and therefore paleontologists find more teeth than anything else from hundreds of years ago. Shubin explained the different types of teeth and how you can differentiate the type of animal, it's diet, and whether or not it was a mammal. Shubin shared stories of his fossil hunting expeditions and also explained where exactly teeth came from and their importance. Teeth usually do not get as much praise as they need as most bones actually come from them and many do not realize how much an old tooth can tell us. The overall point of this chapter was to explain the importance of teeth to evolution. It helps explain the evolutionary history of the human body by how teeth started to adapt to specific needs and diets. For example, for humans, we have incisors, canines, pre-molars, and molars, each of them serving different purposes.

            The most interesting concept presented in this chapter for me was the fact that you can tell whether an animal was a mammal or not by their teeth. I had always known it was the hardest part of the body and therefore could be easily fossilized. I had also known that you can tell which kinds of animals the teeth belonged to and it's diets by the shapes of the teeth because every different type of tooth serves a special purpose. Being able to tell whether an animal was a mammal or not, however, was a very interesting fact to me because I had always known as mammals being animals who give birth through the womb, not born through eggs, and it seemed odd to think you can tell that from teeth. But from the way Shubin explained this concept, I understood it fully. I feel like this chapter relates most with Big Idea #1 because of the evolutional aspect of it. The chapter shows that your teeth continue to change and evolve due to your dietary habits, which is why most herbivores have more molar-like teeth and carnivores have sharper teeth.

YIF: Chapter 3 Review



What makes us look the way we are?

            In a smooth transition from chapters two to three, Neil Shubin furthered the search for "our inner fish" by going one step deeper into the body, from bone structure to the cells and proteins in charge of building our hands. To explain this concept, some background is included, debriefing a short history lesson in how researchers and scientists found out parts of the DNA especially looking into what makes our pinkies look so different from our thumbs. Work of Edgar Zwilling, John Edwards, and Mary Gasseling led to the discovery of ZPA, a patch of tissue that is responsible for the pinky side of a hand to look different from the thumb side. Years later, Andy MacMahon, Phil Ingham, and Cliff Tabin discovered the set of genes that controlled the ZPA, called hedgehog. The overall point to this chapter is to show that the human relationship with fish are not just bone deep, but can go all the way down the our cells. This hedgehog gene was found in all animals, proving that at some point we all came from one. It helps explain the evolutionary history of humans by showing how we all share the same gene.


            I thought that the most interesting concept of this chapter was that a single gene is the reason for how our hands look, and when its location is changed just slightly, suddenly our hands would have a mirror image of fingers. It just seems so weird and cool to me at the same time that the digits would be a perfect mirror image. I had always imagined that, if there had been a case such as this, the other set of fingers would still look like fingers, but would not be a perfect mirror image, maybe just digits of different lengths. Though this book is mainly about evolution, I feel that the facts, thoughts, and ideas of this chapter connect more towards Big Idea #3. I believe this because this idea 

YIF: Chapter 2 Review



How did the simple fish fin evolve into the unique human arm we have today?

            The overall point of chapter two of Neil Shubin's Your Inner Fish was to show one of the connections between the human body and that of the ancient fish. This chapter helps explain the evolutionary history by first introducing the chapter with Shubin's personal account of dissecting the human body during medical school. From there, the importance and uniqueness of the wrist is made and the chapter unfolds on the expedition to find the fossil of a fish that had both fins and limbs, a clear evolutional transition from fish to man. The chapter talks about how they found fossils that didn't fit the criteria they were looking for, a fin that had the single base bone (the humerus),  then the two bones (the radius and ulna in the human skeleton), and then the many smaller bones. Though they found many bones from the correct time frame, they did not have the right bone structure. The fossil they had finally found to fit the criteria was Tiktaalik, which had a flipper like fin with the human arm bone structure.

            The most interesting concept in this chapter was the fact that in the process of evolution, bone structure evolved before such as fingers. I had always imagined that in the slow evolution from fish to human, the fins would slowly turn into hands and fingers. I hadn't expected it to be possible for a fin/flipper to have the human bone structure inside. Of course, I have limited knowledge on this topic, so my imagination had gone somewhat wild trying to visualize what full evolution must've looked like. But it was still very interesting to realize that I had been wrong, and to learn how things actually worked out. The facts in this chapter seemed to connect towards Big Idea #1 more than any of the others because the chapter is still discussing the evolution of life, and how the author and his team had been looking for a specific fossil. An example of how it connects with Big Idea #1 is how they had found that in fish, specifically in the fins/arms, the single base bone was the first to evolve in the fish fin, with another single bone afterwards, followed by the many small bones. Only afterwards did the two forearm bones evolve, the ulna and radius in the human arm. 

YIF: Chapter 1 Review


            How can we learn more about ourselves through of ancient fossils?

            The overall point of chapter one of Neil Shubin's Your Inner Fish is to explain to the reader the connection between ancient fossils and today, whether they be from the species or not. He wants us to know that once upon a time we were all one, and from that one species thousands of years ago, different species and different types of animals have evolved and developed, going extinct and thriving, and finally getting to where we are today. He introduces what he will be talking about in this book by explaining that we can find our evolutionary history through fossils of ancient fish. This helped explain the evolutionary history of the human body to me because when I had first started reading this book, I didn't know that we were this closely related to fish. In this chapter, the concept that was most interesting to me was his basis for the story about Tiktaalik. I thought it was so interesting how these paleontologists had found the earliest fish that were most related to what we would think of as fish today, and then the fossils of  the more developed ones, the ones that would have a bone structure closest to ours. They had such a hard time, though, trying to find the fossil of a new fish that was in intermediate between the two different kinds of animal. The idea of this itself is fascinating, that fish slowly evolved into man, and that if you are determined and look hard enough you can find physical evidence of this slow but steady transformation.

            The theme from this chapter is about how we all are from the same basic family and all grew from that one [fish]. Because of this theme, this chapter helped me make the connection most closely to Big Idea #1. This idea states that the process of evolution drives the diversity and unity of life. This is almost perfectly resembles this chapter because it is talking about evolution and how that is what causes all diversity in the world, yet we are all still united.