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Friday, March 25, 2011
Starting Up Fresh
In Chapter 1, Shubin talks about how paleontologists first begin to hunt for fossils, with the hardships they face. However, there are no mention of the regulations they face, such as limitation of where they can dig for fossils. Discuss what would happen if the rookie paleontologists such as Neil Shubin's gang accidentally stumble upon a fossil that was very valuable (ex. tiktaalik), but their preservation of the fossil was poor because it was on such a spot that limited them in terms of time (ex. side of the road). John Park (wisejsm@yahoo.com)
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As Neil Shubin has already stated, fossils are hard to find because these fossils have to be found in sedimentary rock. This rock is found in bodies of water are or were and fossils are discovered where the water has dried up and the land is being eroded. The problem here is that one, there are limited places where the water has dried up, and secondly, humans inhabited a large amount of these areas, destroying all fossils in the area.
ReplyDeleteAnother problem is that strata (layers of sedimentary rock) are unveiled over time. Therefore, many species will not be found for years because they still have not eroded, revealing the fossils, therefore leaving much of the first creatures still left to not be found.
Another problem, is that if scientists miss one generation of creatures, the cycle of evolution becomes blurred as the principle of uniformitarianism is enforced (the belief that changes in creatures happen over time and are based off another creature's characteristics). By not being able to understand where the roots of each organism come from, it is hard to understand what caused these evolutionary changes.
Some of the physical dangers that the scientists had to endure in order to find these fossils were often more extreme than their bodies were prepared to endure. Other organisms (including the ones they were digging for) could handle these extreme temperatures because there is a "match of organisms to their environments" (Campbell).
The cold temperatures could have easily caused frostbite. Frostbite occurs because there are a lot of blood vessels and nerve endings flowing through one's appendages like fingers, nose, toes, ears, etc. Therefore in cold whether, ones body constricts blood vessels, making the appendages less warm and causing the skin tissue to get damaged from severe coldness. Hunter's response is activated at the extreme coldness that the scientists in the book were at which causes, "Periods of dilatation [...] cycled with times of constriction in order to preserve as much function in your extremities as possible" (http://www.emedicinehealth.com/frostbite/article_em.htm). This occurs until their bodies become at an extreme risk of developing hypothermia (which Hunter's response makes faster).
Jackie James (jackie.james@comcast.net)