The RNA World: The Implications and Problems it Presents
Brandon Gutierrez
Abstract The origin of life on Earth is a difficult topic to analyze with the limited data available in modern science. Many hypothesis have been suggested to explain how life may have arisen from an abiotic environment, but the topic is still far from fully understood. One generally accepted hypothesis to explain the origin of life involves an RNA world in which RNA was synthesized abiotically and carried out both the catalytic function and information storage necessary to support the first living cells. While this hypothesis is fairly well supported, there are some aspects of it that are difficult to reconcile with modern scientific evidence. In this review, I analyze …show more content…
Cytosine is known to undergo spontaneous deamination in the presence of water, resulting in uracil (Shapiro and Klein, 1966; Shapiro and Klein, 1967). Without modern repair mechanisms, this process would be difficult for an early RNA world to manage without severe mutational repercussions. Cytosine has a predicted half-life of 340 years at pH 7 and 25°C, which can be reduced in the presence of various other buffer solutions (Levy and Miller, 1998). In addition to deamination in the presence of water, Cytosine is reactive in the present of UV light, which was unfiltered on early Earth due to a lack of atmosphere (Blackburn and Gait, 1996). The only way to avoid the additional stress of UV light would be for life to have arisen in the …show more content…
and Miller, S.L. The Origin and Early Evolution of Life: prebiotic chemistry, the pre-RNA world, and time. Cell 85, 793-798 (1996).
Levy, M. and Miller, S.L. The Stability of the RNA Bases: implications for the origin of life. Proc. Natl. Acad. Sci. 95, 7933-7938 (1998).
Mielke R.E., Russell, M.J., Wilson, P.R., McGlynn, S.E., Coleman, M., Kidd, R. and Kanis, I. Desing, Fabrication, and Test of a Hydrothermal Reactor for Origin-of-Life Experiments. Astrobiology 10, 799-810 (2010).
Miller, S.L. A Production of Amino Acids under Possible Primitive Earth Conditions. Science 117, 528-529 (1953).
Mulkidjanian, A.Y., Bychkov, A.Y., Dibrova, D.V., Galperin, M.Y. and Kooning, E.V. Origin of First Cells at Terrestrial, Anoxic Geothermal Fields. PNAS 10.1073/pnas.111774109 (2011).
Orgel, L.E. Some Consequences of the RNA World Hypothesis. Origins of Life and Evolution of the Biosphere 33, 211-218 (2003).
Schopf, J.W. Microfossils of the Early Archean Apex Chert: new evidene of the antiquity of life. Science 260, 640-646 (1993).
Shapiro, R. Prebiotic Cytosine Synthesis: a critical analysis and implications for the origin of life. Proc. Natl. Acad. Sci. 96, 4396-4401
Brandon Gutierrez
Abstract The origin of life on Earth is a difficult topic to analyze with the limited data available in modern science. Many hypothesis have been suggested to explain how life may have arisen from an abiotic environment, but the topic is still far from fully understood. One generally accepted hypothesis to explain the origin of life involves an RNA world in which RNA was synthesized abiotically and carried out both the catalytic function and information storage necessary to support the first living cells. While this hypothesis is fairly well supported, there are some aspects of it that are difficult to reconcile with modern scientific evidence. In this review, I analyze …show more content…
Cytosine is known to undergo spontaneous deamination in the presence of water, resulting in uracil (Shapiro and Klein, 1966; Shapiro and Klein, 1967). Without modern repair mechanisms, this process would be difficult for an early RNA world to manage without severe mutational repercussions. Cytosine has a predicted half-life of 340 years at pH 7 and 25°C, which can be reduced in the presence of various other buffer solutions (Levy and Miller, 1998). In addition to deamination in the presence of water, Cytosine is reactive in the present of UV light, which was unfiltered on early Earth due to a lack of atmosphere (Blackburn and Gait, 1996). The only way to avoid the additional stress of UV light would be for life to have arisen in the …show more content…
and Miller, S.L. The Origin and Early Evolution of Life: prebiotic chemistry, the pre-RNA world, and time. Cell 85, 793-798 (1996).
Levy, M. and Miller, S.L. The Stability of the RNA Bases: implications for the origin of life. Proc. Natl. Acad. Sci. 95, 7933-7938 (1998).
Mielke R.E., Russell, M.J., Wilson, P.R., McGlynn, S.E., Coleman, M., Kidd, R. and Kanis, I. Desing, Fabrication, and Test of a Hydrothermal Reactor for Origin-of-Life Experiments. Astrobiology 10, 799-810 (2010).
Miller, S.L. A Production of Amino Acids under Possible Primitive Earth Conditions. Science 117, 528-529 (1953).
Mulkidjanian, A.Y., Bychkov, A.Y., Dibrova, D.V., Galperin, M.Y. and Kooning, E.V. Origin of First Cells at Terrestrial, Anoxic Geothermal Fields. PNAS 10.1073/pnas.111774109 (2011).
Orgel, L.E. Some Consequences of the RNA World Hypothesis. Origins of Life and Evolution of the Biosphere 33, 211-218 (2003).
Schopf, J.W. Microfossils of the Early Archean Apex Chert: new evidene of the antiquity of life. Science 260, 640-646 (1993).
Shapiro, R. Prebiotic Cytosine Synthesis: a critical analysis and implications for the origin of life. Proc. Natl. Acad. Sci. 96, 4396-4401