In chapter four, Shenk addresses the idea of how the environment can drastically change the body type of person. On page 266, Michael Rennie wrote that the body type is influenced half by environment and half from genes. If two identical twins have the ability, “to sculpt their bodies by different training regimes” (266) which gives two different body types.
How does this idea of having the environment shape the body relate to the theme of relationship between structure and function? If the environment is the same could people have the same body type if they followed an identical lifestyle? Do you think animals have the same ability to change body types due to the demand from the environment?
How does this idea of having the environment shape the body relate to the theme of relationship between structure and function? If the environment is the same could people have the same body type if they followed an identical lifestyle? Do you think animals have the same ability to change body types due to the demand from the environment?
Campbell talks about Darwin’s Origin of Species in chapter 22. In his book, Darwin talks about the concept of adaption “characteristics of organisms that enhance their survival and reproduction in specific environments” (456). Perhaps the most iconic of Darwin’s observed species are the finches of the Galapagos Islands. William J. Cromie is a member of the Harvard News Office and he posted an article about how Darwin’s finches got their beaks. Harvard researchers believe that “calmodulin [behave] as the switch that can turn on genes involved in increasing beak length”. Higher levels of calmodulin could be the cause of longer beaks in finches. But the reason some finches had long beaks and others had blunt one was due to the environment. This is how structure and function are connected to the environment. Since long beaks are “more fit for picking seeds out of cactus fruits” and short ones “served best for eating seeds found on the ground”, then a species that had the appropriate adaption for their environment passed on their genes while the rest went extinct. This is how animals also have the ability to adapt their bodies over time to their environment. Humans also have gone and continue to go through natural selection in the same way.
ReplyDelete(http://www.news.harvard.edu/gazette/2006/08.24/31-finches.html)
In his book, Shenk talks about the story of Jim Springer and Jim Lewis, long lost twin brothers who meet up in 1979. Journalists loved to publish the story of how even twins separated could share the same looks, tastes, and dialect. But Shenk found this event not so surprising by saying that identical twins who “shared a womb for nine months and a month more in the same hospital, and were raised in working class towns” (83) being very similar was not so surprising. Perhaps it is possible for people who live in the same environment and lead similar lifestyles to match each other in various aspects, provided they also have the same DNA sequence. In any identical twin study, the given is that their DNA is close enough matched that their major difference is probably due to environmental causes. But if you took people with separate origins living the same lifestyles in the same environment, their personality similarities is outweighed by their genetic differences.
Alvin Varghese (alvin.varghese@hotmail.com)
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ReplyDeleteAn organism's body is made up by a mix of genetics and environment as stated, but the overall result of one's body shape and tone comes from what the environment makes them do. If an organism is not born with the genetic make up in which it is naturally strong, but it lives in an environment which requires it to be strong and survive, then it's body will adapt. For example, it is not possible for every lion to be born naturally strong and be able to hunt anything without any experience. Through the process of hunting and surviving the lion will build itself and eventually reach a body that was created by genetics and environment.
ReplyDeleteTheoretically, if two idential twins with the exact same genes followed the exact same lifestyle, they could develop similar bodies, but this is physically impossible. Even if they follow the same training regiment, there will always be some reason that their bodies will end up differently.
As Shenk said during the skype interview, two identical organisms can never be identically the same even if their genes are exactly the same. He gave the example of the two cats, rainbow and CC. CC was named CC because it was supposed to be a carbon copy of rainbow. Although both cats had the exact same genetic make up, the cats had different eye color and fur color. This means that they must have been brought up different during development and naturally adapted to their environments.
Alvin brings up a good example with the finches in the Galapagos Islands because the species of finches were able to change their body type over centuries due to natural selection. Since certain beaks were better suited for certain environments, their body type changed as the less well off beaks went extinct. Just as the structure of strong forelegs in lions developed due to the need to hunt (http://www.honoluluzoo.org/lion.htm), the finches developed beaks based on what would be better to survive.