Data Bases • Custom Term Papers • Free Term Papers • Free Research Papers • Free Essays • Free Book Reports • Plagiarism? Links • Top 100 Term Paper Sites • Top 25 Essay Sites • Top 50 Essay Sites • Search 97,000 Papers @ DirectEssays.com • Search 101,000 Papers @ ExampleEssays.com • Search 90,000 Papers @ MegaEssays.com Free Essays • Term Paper Sites • Chuck III's Free Essays • Free College Essays • TermPaperSites.com • My Term Papers • Get Free Essays • Essay World • Planet Papers	Search Lots of Essays Back to Subjects - Science Gaia Gaia John Lovelock in his book The Ages of Gaia presents an argument for a theory governing the relationship between the earth's biota and its physical environment. Lovelock holistic view of nature combines biology and geoclimatology as one science, which he calls geophysiology, “the study of living and non-living Earth as a single system (Lovelock 11).” Lovelock’s theory states that life is necessary to maintain the planet’s thermodynamic and chemical composition in its current state of homeostasis (the tendency of a system to maintain stability even with external disruptions) until some external force interrupts it, at which point it will move to a new stable state. He terms this theory “Gaia”, after the Greek goddess of Earth. The Gaia theory delivers two primary implications: living organisms regulate their planet, and the evolution of species and their physical surroundings are a single inseparable process. The hypothesis points to stable conditions, such as oxygen levels, carbon dioxide concentrations and climate, as evidence that living organisms maintain a life-sustaining environment. The Gaia Hypothesis is a metaphor in itself that helps describe the planet as a living organism; a metaphor for the Earth as seen as a single physiological system. Lovelock describes the planetary ecosystem as alive because it behaves like a living organism by regulating its temperature and chemistry at a constant state favorable for life to develop. Another metaphor used by Lovelock is Daisyworld. Daisyworld is a computer-stimulated model of an imaginary planet developed by Lovelock to specifically demonstrate his Gaia hypothesis. In this model, Lovelock presents the behavior of the theoretical planet Daisyworld where the environment consists of a single entity (planetary temperature), and the biota consists of only two species: dark daisies that absorb radiation, and therefore warming the planet and light daisies that tend to reflect light, which has a cooling effect. Like the earth, Daisyworld maintains a constant temperature and the conditions for its survival by following its own natural processes. In the past, when the sun was not as bright as today, dark daisies flourished because they were able to absorb the warmth from the sunlight. The dark daisies gradually took over most of the planet, increasing the planet’s climate. When the suns intensity increased, the lighter daisies began to flourish by reflecting light and cooling the planet. Thus, the population of the light and dark daisies adjust themselves naturally to keep the temperature constant at the optimal level for daisy growth. In this way, Daisyworld is a metaphor for a self-regulating system, as predicted by Lovelock’s Gaia hypothesis. The Selfish Gene gives a very different view of the evolution of life. Dawkins presents a reductionist view in his theory that genes are the primary mode for natural selection and evolution. Dawkins looks at the evolutionary process, how DNA replicates in forming human life, and the possibility that there is a social parallel to genetics where human traits can be culturally transmitted. Dawkins’ book also delivers two primary implications: that evolution takes place entirely through the effects of natural selection and propagation of genes and that genes are selfish, not altruistic. Dawkins states that evolution began in the ancient seas. He uses the metaphor “primordial soup" to describe the contents of the seas before living things came about. In this “primordial soup,” protein molecules randomly bonded together to form "replicators," DNA. Dawkins states that there was an unconscious struggle for survival amongst the replicators. He then goes on to link the behavior of genes to human behavior and personality by introducing the concept of a “selfish gene,” where he defines “selfish” as a gene strategy to ensure its survive over its rival alleles. His use of the term “selfish” personifies genes as an individual, capable of making decisions for its own good. In his opening statement, Dawkins states, "we are survival machines-robot vehicles blindly programmed to preserve the selfish molecules known as genes" (Dawkins vii). By calling human beings "survival machines" and "robots," Dawkins implies that we are not in control for our own actions. Again, his metaphors takes the reader away from his scientific reasoning and make them think of a distinct individual that is pulling the strings of evolution for its own good. This statement also conjures up moral implications that suggest that we are not in control of our lives and there is no point for our own existence. The point Dawkins wants to make is that metaphorically genes do possess a selfish ability. However, Dawkins’ metaphors make it difficult to remove the selfish gene theory from its moral implications. Bibliography: WORKS CITED Dawkins, Richard. “The Selfish Gene.” Oxfod University Press, 1989. Lovelock, James. “The Ages o Word Count: 755
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