chapter four

In this chapter Shubin first mentions a lot about learning from others the different processes and techniques to finding fossils. First he took small steps by recognizing the visual cues that distinguishes bone from rock. Then, he was able to develop what he called a search image that could guide his search. I thought this reflected the systematic way of thinking that scientists need to be able to discover new things (kind of like the scientific method I guess). It also showed the unyielding patience that one has to have in order to find fossils, and that a scientist cannot expect to find new fossils or any discover any connections to the human body if he disregards even a single detail. This is especially shown when Shubin says, "I'd scrutinize the whole thing on my hands and knees, with my eye and hand lens only about two inches from the surface of the ground" (66). This then reminded me of how it takes a lot of practice, patience, and experience to become good in anything.

I already learned from my dentist that teeth reveal a person's lifestyle and diet. But it surprised me when Shubin mentioned that"teeth are the hardest part of our bodies" (61). I thought they were just the same as the other bones of the body; that's something the dentist didn't tell me. Also, when he talks about the "precision with which we chew" (61). He describes, "In tritheledonts, individual cusps do not interlock in a precise way, as they do in mammals" (72). Only then did I realize the importance of aligning the ridges and the cusps to eat with maximal efficiency and not shatter the teeth. This kind of made me appreciate and be more thankful I had braces. Another surprising thing was that "We would never have scales, feathers, or breasts if we didn't have teeth in the first place. The developmental tools that make teeth have been re-purposed to make other important skin structures" (79). I know teeth are important, but who would have thought that teeth are the origins of so many other different things?
I like how Shubin connects the first four chapters in theme and actually uses theme itself to exemplify all the different organisms of the world and really show that we are all "just variations on a theme" (80). This book just keeps getting even more interesting with every chapter!

Alexis Jacalne