Ch 6: The Best-Laid (Body) Plans

I just love the way Shubin describes everything so simply. He always finds some way to relate the human body to other creatures such as lizards. Who would have ever thought that our human embryo would be similar to that of a chicken? I found it hard to believe. Von Baer's and Pander's experiments on chicken embryos brought about the three germ layers. The way Shubin describes that "[...]every animal originated in one of these layers" (99)truly was shocking to me. It was kind of frightening to find out that, "[...]When a blastocyst implants in the wrong place-- when there is an "ectopic implantation"--the results can be dangerous" (100). So many of the discoveries in these chapters was shocking. Such as that some creatures don't have an anus but have a mouth. Also, the fact that most of the discoveries about our human body came from flies was utterly shocking. It was interesting to know that if you took a tiny piece of tissue from one embryo and graft it on an embryo of another species, the, "[...]grafted patch led to the formation of a whole new body, including a spinal cord, back, belly, even a head" (106). How interesting is that? Very. It is interesting how Shubin relates all previous chapters into his other chapters. Such as how he ties genes and evolution to this chapter. He explains how our bodies are modified through the years. This chapter was too good. I can't wait to read chapter seven.

Chapter 6: The Best-Laid (Body) Plans

It's amazing that in just 5 days, a single body divides 4 times to produce a ball of 16 cells, the blastocyst. To add to that, Shubin introduced to me that an entire body forms only from the ball embedded in the wall of the uterus. I was always unable to fully grasp that the complicated human body was created starting from the embryo, but now, I know that the obscure human body was developed from only the top part of the blastocyst and not all of it. I still can't wrap around the thought that a "Frisbee" (101) like thing can become a fully developed human being. If it wasn't for Shubin, I would never have known that we have a "tube-within-a-tube" (101) structure in us. In addition, I would never have known that pinching one side of a newt egg from the other would make twins. It's amazing that a single small piece, the Organizer holds the future structure and development of the germ layers that makes up the whole body.

Chapter 6

An experiment with chicken embryos led to expeditions of fish reptile and other mammals embryos. Von bear found similar points in organs of all the different species. This chapter was interesting because it explained to us how our bodies are structured and the creatures who have the same structures as us.Our bones and their structure are made with different skeletal tissues and cartilage that are present to help our bodies function the way they do. Our bones are made for pulling and compression.cells in our body are packaged to help us function and opperate properly. Without them we wouldnt be able to function.

Chapter 6

This chapter was interesting for me in one dynamic way-by way of help. I liked how the affluence of Christian Pander opened many doors for von Baer. Von Baer was not financially capable to complete the experiments that he needed but help was there to aid him. One affordable experiment with the chicken embryos led to expeditions on other embryos, that of fish, reptiles, and other mammals. With his multiple experiments, von Baer found that the different species had similar points of origins for certain organs. This was apparently new news to me because I had never thought that different things in life can have similar to same points of origins...in the world of math yes but all else no.

Chapter 6

Starting of chapter six was very interesting because it started out how our bodies are structured and then started giving us examples of creatures like us. When i started reading the common plan:comparing embryos i thought i was reading an actual story which got me addicted in reading this chapter more. I like shubin's writing style because at first he starts out with a story and then as the process moves on he changes it to actual facts. Sometimes he also might even end up telling a story about his colleagues and what they had did in the matter of his research. When shubin started talking about our bodies and how they are useful he gives us many diagrams to help us get a better idea on how it all works out. For example the diagram of the first three weeks after conception,which helped me understand how our small cell ends up forming as a tube. An amazing part of this chapter was of flies and men, this got me intrested because i read how a small embryo of a human with a undeveloped back becomes a fully grown human baby with a perfectly normal back. As a result i enjoyed reading this chapter and i cant wait to read the next one.

Chapter Seven: Adventures in Bodybuilding

When Shubin explained that this chapter was going to be about the when, how, and why of bodies I was interested. But after the first couple pages I lost that interest. I don’t really know why but I kept losing focus and my mind would go off into other directions. The only subject of this chapter that I wanted to read was the why. I find it funny that a scientist disproved another’s assumptions, which show that science isn’t always an exact science. That scientist are proving and disproving theories and assumptions all of the time. I like how Shubin broke down how our bones work. What the bones’ structure is made for; and that different skeletal tissues like cartilage are present for a reason. That are bones are made for pulling and compression while cartilage is made for movement and flexibility. So finally I got to the last section of the chapter and the big question of why bodies are here. I was disappointed to hear that his big explanation was that we were made to eat other things and protect ourselves from predators. I don’t believe in evolution or that humans were put on this earth to eat smaller creatures - that humans are the champions of some war with other species. Humans were put on this earth to do some better, to create something better, and to live great lives; not because it was a competition.

Chapter 6: The Best-Laid (Body) Plans

This chapter talked about the layout of our body and how all the cells are packaged and assembled inside us. Humans are all created with the same design, symmetrical with a front/back, top/bottom, and left/right. When Shubin compares different embryos of varies species, he realizes that although the species ended up looking different they all started from a generally similar place. They all pale in comparison with their fundamental similarities. Shubin also talks about the three layers of tissue (germ layers) in a developing embryo which all organs in an animal can be traced. Every animal organ originated from one of these three layers. The three layers forms the same structures in every species, every heart formed from the same layer. No matter how contrasting the species look as adults, as an embryo, they all experience the same stages of development. Another factor that reveal how humans are similar to animals is that in the middle of each gene, a short DNA sequence was identical in each species. I learned that this sequence is called a homeobox and the genes that contain the homeobox are called Hox genes. It fascinated me how Shubin is able to compare and connect us to every possible creature out there, possibly even jellyfishes.