Better Late than Never

Firstly, I apologize for my tardiness in contributing to this blog, I had just returned from Europe thursday night.

It's too late to post anything for chapters one and two, but I did read them. Chapter three was extremely interesting. To be honest, it is the first chapter that actually captured my undivided attention. The first two chapters seemed to drag on, but this chapter was fascinating from beginning to end. The idea of ZPA and Sonic Hedgehog captured my imagination. Are these two genes responsible for the deformities in humans-extra head, siamese twins? If so, scientist can prevent these problems by examing human embryos and making sure that ZPA and Sonic hedgehog exist at a normal level in embryos. Although it is cruel to use countless animals as guinea pigs, we can now thank these animals for helping us understand how to prevent human deformities, if the genes are involved. It is remarkable in how organized our bodies are, always striving for perfection. Whenever I see an animal or human being with double of any limb, I will always be wondering whether the being in question had a little bit two much ZPA or if it's Sonic Hedgehog had activated or not.