AP/IB 11 Biology
Origins of Life on Earth
There are multiple theories as to how life began on earth, beginning with the findings of various revolutionary scientists. This paper will discuss various scientists' theories and experiments as they strove to discover how life began, and the processes that might have occurred in order to develop and create the world we are now familiar with today. Recent discovered functions of RNA have suggested that RNA provides a crucial framework in the evolution of the first cells, which may have been assembled from RNA comprised of nucleotides. Sidney W. Fox, a scientist at the University of Miami produced membrane-bound structures known as proteinoid microspheres. These microspheres can carry out some chemical reactions that resemble real living cells. They grow slowly and eventually bud off smaller microspheres. They're not living cells, but they are key in determining the kinds of processes that could have given rise to “self-sustaining protein entities”. It has even been hypothesized that comets and meteorites containing carbonaceous material hit the Earth with great force, and may have been a source of organic compounds such as lipid-like materials. David W. Deamer at the University of California and his co-workers extracted these organic materials from the carbon containing meteorites. Inevitably, some of the molecules assembled into membrane-bound spheres, possibly signifying that this might be how first primitive cells conglomerated. This then brings us to the theories of influential scientists, Russian A.I. Oparin and British scientist J. B. S. Haldane, who hypothesized that earth's organic molecules were formulated from simple molecules. Both Oparin and Haldane postulated that earth was a reducing agent, in that electrons could be added; the energy from this could have come from lightning and intense UV radiation. In 1953, Stanley Miller and Harold Urey conducted an experiment to test what was deemed as the...
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