Chapter Six

In the beginning of Chapter 6, the author had illustrated about the embryos of many kinds of animals. One of the points he mentioned, which I thought it was quite interesting, was that some of the animals’ embryos were not many differences, but they had all grown out and become various animals. In fact I’ve never thought about how animals were so similar when they were embryos. So I was wondering if all of us; including other mammals and reptiles, had similar embryos, and might have been evolved from the same kind of creature. This means, maybe, once we were relatives since we had the same ancestor.

On the other half section of this chapter, Mr. Shubin had brought up that all kinds of animals contained the organizer, which helped us with the development of inside body parts, and had many remarkable meanings. One of the most significant meanings about the organizer was happened at the middle part of genes of its DNA. These parts of the genes were called the Hox genes. There was a special finding about Hox genes which attracted me very much. The author had pointed that most of the animals contained the similar sets of Hox genes. That’s why, some of the animal’s embryos look similar because of the common sets of the Hox genes they contained, but why did they have the different outcomes? The author had answered this question by explaining that it is because the amounts of the common sets are different, and that’s why the outcomes are not likely. So now, we could understand why different species of animals have their own unique looks. The other main finding that I could not even think about it before read this chapter was that some of the animals’ embryos look similar. Amazing!