CHAPTER 1This graphic shows the fossil Tiktaalik. The text describes the importance of this fossil and how the fossil is the first representation of evolution from fish to amphibian that the author’s paleontology group discovered.The statement above is false because after the death of said animal, there are factors that could prevent the remains to fossilize, and factors that affect the condition of the fossil. These factors include the environments of the rocks formed, some rocks, such as volcanic rocks, igneous rocks, and metamorphic rocks, are impossible to survive in the superheated conditions of said rocks.
The author and his colleagues chose to focus on 375 million year old rocks in their search for fossils because the fossils that were discovered in 385 million year old rocks resembled fish, and fossils that were discovered in 365 million year old rocks included a diverse group of fossilized animals, such as amphibians, it would be inferred that the representation of the link between fish and amphibians would be discovered in rocks around 375 million years old.The fossil Tiktaalik had scales on its back and fins with fin webbing, like a fish, it also had a flat head, a neck, and an advanced bone structure, like early land-living animals. This fossil confirms a major prediction of paleontology in that it showed characteristics from two different kinds of animals, fish and amphibians showing an evolution.
Neil Shubin thinks Tiktaalik says something about our own bodies because the Tiktaalik has similar features to humans, and describes the similarities such as the bendable neck, and other parts of the skeleton. These similarities help emphasize the theory that humans have an ancestral connection to the Tiktaalik or a similar animal.CHAPTER 2The graphic relates to the text because it shows the muscles and tendons of the hand, and the text describes the complex interplay among muscles, tendons, and bones in the hand within each movement.The statement “Humans and fish are nothing alike: we have fingers, they have fins,” is false because although the physical appearance of hands and fins are different, they are similar in that they have one common bone. The humerus is a bone in the arm or femur in the leg, that articulates with two bones, which attach to a series of small blobs that connect the fingers or toes.
Whether it be a dinosaur, bird, fish, whale, or human, the order of the bones is the same, one bone, followed by two bones, then little blobs, then fingers or toes.Charles Darwin’s theory explains these similarities that were observed by Owen by explaining how “the reason the wing of a bat and the arm of a human share a common skeletal pattern is because they shared a common ancestor.” Darwin also explains how this same reasoning can be applied to everything that has limbs. Further examination of Tiktaalik’s fins, a wrist was revealed that Tiktaalik had wrists. This discovery provided the information to conclude that this animal was likely built to navigate the bottom and shallows of streams or ponds, and even on the mudflats along the banks. CHAPTER 3The graphics relate to the text because the first graphic is an image of a Sonic Hedgehog, and the second graphic is an image of DNA with a on and off switch on it. These images demonstrate the relationship between DNA and the Sonic Hedgehog gene. For example Shubin explains that if Sonic Hedgehog hadn’t turned on properly during the eight week of your own development, then you either would have extra fingers or your pink and thumb would look alike.
The statement above is false because each cell in a human body does NOT contain a unique set of DNA because all the cells in your body contain the same DNA. Genetic switches control the activity of genes in cells and tissues. The zone of polarizing activity, or ZPA, is a patch of tissue that causes the pinky side to be different from the thumb side. CHAPTER 4The graphic relates to the text because the text describes the importance of teeth, their history, and the evolution of teeth, and the graphic shows a dentist which is a person specialized in teeth and gums.The statement above is false because teeth weren’t used for protection, their main use was for eating. The first example was a tiny mammal that had lived 190 million years ago, which showed patterns of chewing. Shubin explains “Hard bones arose not to protect animal but to eat them,” then describes how teeth and bones change the competitive landscape.
When Shubin writes that “we would never have scales, feathers, and breasts if we didn’t have teeth in the first place,” on page 79, he later explains how the “key to teeth development” is the exact same process that is used to create all the structures that develop within the skin, such as hair, feathers, and glands. Shubin also explains that the process for making teeth was first so therefore all of these bodily structures were created because of the development of teeth. CHAPTER 5The graphic represents the term “your inner shark” which means we share similarities with sharks.
These similarities include the basic plan of the human head.The statement above is correct in that “humans and sharks both have four gill arches as embryos,” although the second part “the germ layers and arches develop into unrelated structures in each organism,” is incorrect. The first gill arch in both humans and sharks have a similar state of affairs: jaws. Although the difference is that a humans’ first arch also forms ear bones which does not happen in sharks. In humans during the second arch, the cartilage bar breaks up to form one of three bones of our middle ear, the stapes, and other small structures t the base of the head and throat. In a shark, the second arch rod breaks up to from the bones that support the jaws: a lower one and an upper one. The third and fourth arches in a shark, support the gills.
In humans, the third and fourth arches are where structures that are used to talk and swallow are. The trigeminal and facial cranial nerves are both complicated and strange in the human body as Shubin says “nothing about them seems to make any sense” and begins to give examples of the confusing nerves’ descriptions, such as the nerves sending tiny branches to muscles inside the ears, when each nerve controls different parts of the face and jaw.During the first of four embryonic arches in human development the upper and lower jaws, two tiny ear bones, and all the vessels and muscles that supply them are formed. During the second arch the third small ear bones, a tiny throat bone, and most of the muscles that control facial expressions are created.
During the third embryonic arch bones, muscles nerves deeper in the throat that are used to swallow are made. Lastly, during the fourth embryonic arch the deepest parts of the throat, such as the larynx and the muscles and vessels that surround it, are developed.Hox genes are eight genes that contain the homeobox, a short DNA sequence that was virtually identical in each species observed. They are so important because they establish the proportions of the body. Amphioxus is a small invertebrate yet an important specimen for study because their fossils preserve finely detailed.
These worms also are the earliest creatures with notochords and nerve cords. CHAPTER 6The recipe for Chocolate Chip Cookies relates to the text in that, Shubin compares a recipe that that is passed down from generation to generation, with enhancements made, with evolution or a “recipe that builds our bodies that has been passed down, and modified, for eons.” The statement is incorrect because when repeating experiments, the accuracy of said experiment increases, and it can help prove the hypothesis, and make new findingsSea anemones have radial symmetry while humans have bilateral symmetry, but they still have “similar” body plans because they have a front and back as we do, this body plan was set up by versions of the same body-building genes.
