Ch. 3

From this chapter, i stand in awe at the complexity of our bodies. That a single piece of tissue, the ZPA, could drastically alter the anatomy of our hands. To think that the presence of that little tissue determines whether we end up with normal hands or mutant hands with multiple or missing fingers, or no hand at all. It truly amazes me that a single tissue plays such a role in our bodies. I agree with iris that our bodies are so complex that we need everything to be perfectly in place or we turn out with mutations and drastic changes to our body. Moreover, who knew vitamins could influence developing embryos in such a way. As a shubin said, with a certain amount of vitamin A at a certain time, will also alter the developing embryos fingers.
When shubin talks about all the scientists' experiments on the flies, chickens, and skates, it shocked me how experiments on these animals could be used to relate to humans. I never thought chickens, let alone flies, could be used in relation to humans, i thought those experiments could only be done on monkeys since they resemble us more and can be related to better. As a result, that means the results that happened on those animals means that it would also happen to us humans since the ZPA and sonic hedgehog gene was found in all the subjects. And that kinda means that we can create our own freaks of nature since we know that removing the ZPA from one part of a specimen's limb to another will result in double the amount of fingers.
Lastly, the fact that these genes were found in all the test subjects and us humans as shubin said, shows us how truly connected we are to the animal world. Although on a superficial level we may not look the same or related to other species, but on deeper level on our genes and DNA, we see that we aren't as different from animals after all; since we share some of the same genes and body structures. That means in a way, we are related to most everything in the world, with limbs anyway. After reading this chapter, i can see now how we have, as shubin said, not only an "inner fish", but an "inner chicken", "inner skate", and even an "inner fly".
-Bryant Wong