Chapter 6: The Best Laid (Body) Plans

This chapter continues to connect the embryo with tissues, genes, and DNA like the previous chapter. However, instead of the specific arches of the head, this chapter describes the source of the overall development of the entire body in an embryo: the three germ tissues. I found it incredible that our human bodies, something so complex, are developed from just three tissues that form our body. Shubin then goes on to describe the how these tissues that are unsurprisingly found in animals with bodies function through DNA and genes. Shubin refers back to the hox genes and attributes them to determining what is formed in our bodies (organs, bones, muscles, etc...) through the germ tissues. However, Shubin pointed out to me that these weren't the only genes in a body's development for a consort of genes such as the Noggin, BMP-4, and the Organizer work together and not separately to build different types of the body (such as when the BMP-4 turns off when the Noggin turns on). Thus far, this applied to animals with bodies like ours and Shubin finally applies our similarities to other types of creatures. Shubin concludes by revealing creatures like the sea anemone have primitive forms of Noggin. I felt this chapter was especially confusing with all the names, but overall, a great learning experience that seemed on topic.

Chapter 6: The Best-Laid (Body) Plans

This chapter basically goes into further depth from the last chapter. Instead of just focusing on what made the head of each species during the the embryotic stage (which I found extremely interesting) I also got to learn how the body was made up. There also seemed to be more to each specie embryo then just arches but instead they had three layers of tissue: ectoderm, enotherm, and mesoderm. They eventually make up the skin, nervous system, organs, guts etc. which was interesting because I really did not know that there were layers or arches. I had just assumed that the body knew what to do and there were no questions about it. But I never knew why the body automatically followed those instructions.

DNA I knew played an obvious role of which gene gets to be in the body...but I did not know about the Hox gene which determined the proportions of our bodies IE. the shape of the chest or head and where they were supposed to go. To get even more in depth there were also the Noggin gene and the BMP-4. Those genes determined which part of the body was the front and which was the back...they each turned itself off when the other one was working. I had no idea that had occurred during the embroytic stage...it answered my question of what exactly happened during that stage of my life. As well I am also glad he had compared humans to invertebrates to see if there were some similarities that could pinpoint how invertebrates work. This was an interesting chapter to read and I look forward to more.

Chioma

Chapter 6: The Best Laid (Body) Plans

The simplicity of many other creatures, initially, makes it difficult for us to concieve them as similiar; however, Shubin described many analogous structures and organizations within our body which closely associates us to these primitive beings. I remember attending a Body Worlds exhibition, daunted and appalled by the numerous authentic human corpses displayed in various life-like poses, yet, I was intrigued by its realness and intricacy. At the exhibit, I was able to observe real, preserved embryos and as Shubin explained the structures of the animal embryos, I reflected back to this tiny, not yet born human embryo. Though they are not exactly alike, the similiarities did seem inevitable. Now, the developing process differs vastly in our coplex system causing the outcome to be indubitably anithetic.

Chapter 6: The Best-Laid (Body) Plans

Personally chapter 6 was incredibly interesting. When I began reading it was mind boggling on how the body is so complex but it all ended up making sense by the way Shubin had explained it. It was kind of crazy imaging that a fish's and an elephant's embryos are so similar even though the two are so different whey are fully grown. Also learning about the germ layers on page 99, which were the three layers of tissue that make up the organs of the chicken and a human made me think that we are so similar to so many different animals even though we don't look like them most of our insides are more similar than different. A apart in the chapter that really surprised me was when Shubin began talking about how files were important which made me realize that maybe i shouldn't be vigorously attacking them when they enter my home. I also didn't think that Shubin would have been able to compare humans to sea anemones but he did. I would have thought that since a sea anemone is so simple it would have no relation to a complex human being but Shubin was able to prove us wrong. One aspect that I love about this novel is that the diagrams usually don't confuse us, and end up helping us realize that what we are reading is what we are looking at. Also throughout this chapter as well as some of the other parts of the book I love the way that Shubin finds ways to compare us to different species such as fish, reptiles, etc. I look forward to keep reading more about how humans and other species are so similar yet so different.

-Neha Modha

Ch. 6: The Best-Laid(body) Plans

The best laid body plans are DNA which is so neatly organized that even the gene that controls the body's development is called The Organizer. This chapter caught my attention because not only was this easily comprehended but also universal to almost every species alive today.
From embryo to newborn, many things occur which all correlate into one complex or simple body. I found it remarkable that the most fundamental material first starting human life can connect to other species much different from humans. Starting off, the embryo doesn't look much different but while in the uterus of our mothers, features start to appear through the development of the three germ layers. The 3 germ layers made the creatures alive today and thus creates two types of growth: "features shared by every species, and features that vary from species to species"(102). this is where we are distinguished from other animals.
so now that we know that the embryo has all the materials to build the body,but how does it know? This is explained very clearly by chronological order and through steps in which various scientists around the world took to figure out not only what gene controlled the on and off functions of others but also the genes that make the features different from one another called The Organizer, Hox genes, and Noggin.
The comparison from the mammal embryos to faceless species was inspiring and beyond what is expected because who would compare some thing that looks so different and expect to find the same basic blueprint? Certainly I wouldn't, but then again, "Don't judge a book by its cover." Shubin told us of the DNA and the symmetry that both the sea anemone and humans share in the orbal-aboral axis and the head-to-anus axis. Faceless and even invertebrates were compared to humans and what next? So much seemingly unrelated species were compared to Humans and have been found very similar to us proving that all of the species around us have been part of the same evolution ladder. Again intriguing maybe I am related to my oldest archenemies: Spiders...

Chapter 6: The Best-Laid (Body) Plans

I thought it was interesting that every species from something as small as a fish to something big as a elephant could all look generally similar as embryos. It was hard for me to imagine that even very different limbs like wings or legs could have ever resembled each other even though it had been as embryos
When it came to the part where Spemann experimented with newt eggs and his daughter's hair. Despite the fact Shubin mentioned that baby hair is remarkable, I thought that the newts would become, for sure, deformed because Spemann had not used "scientific" tools. I also thought it would become deformed because it was divided into two parts "forcefully" not naturally. However, my guess was wrong and I was shocked when two salamanders emerged normally as if nothing had happened.
The passage about Mangold made me furtherly dumbfounded because she took a part of an embryo of a different species and grafted into a species yet the grafted embryos still continued to develop. However, it turned out to be that the Organizer than helped make this possible. As this book progresses, I become lucid in the fact that size especially in the body is not an indication of importance because the organizer is also a seemingly insignificant tiny piece of a tissue but is the main way the embryo forms.
In the previous chapter, it was said that worms without a head are the origins of "the essence of our head" This fact had been surprising but it was even more astonishing that in some ways "primitive versions of some of our major body plan genes" were from sea anemones. The fact that animals that had a jellylike body could be the predecessors of humans that actually had bones was beyond my imagination

Chapter 6: The Best-Laid (Body) Plans

This topic alone about how our body is assembled and what is in charge of building what in a creature can be mind twisting, but Shubin explained the process in a very intersting and easy to understand chapter. I would have never thought that, "All organs in the chicken can be traced to one of three layers of tissue in the developing embryo" (99). Its amazing to see that these three layers or germ layers can be found in every species which shows how undifferent creatures are in the early stages of life. I thought that throughout this entire chapter, the organizer intrigued me the most. Learning how the Organizer could help form an entire body plan could only make me think about the many cartoons that have monsters with multiple heads and limbs. I could not believe what I read about hox genes in flies and people. We look entirely different but in reality theres more connections than I could imagine. My favorite part from this chapter was the connection between a human and a sea anemone. By the looks of it, sea anemones don't share eyes, bones, a heart and several others, but we do share the belly-to-back genes. Even though by appearance creatures from all ranges of life seem to share no connections with each other, inside, there's more interconnections than we can ever imagine.