Difference between revisions of "Eyespot"
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| − | A light-sensitive region in certain [[protozoa]] | + | A light-sensitive region in certain [[protozoa]],<ref>Wile, Dr. Jay L. ''Exploring Creation With Biology''. Apologia Educational Ministries, Inc. 1998</ref> such as Euglena. |
D. E. Nilsson and S. Pelger <ref>D. E. Nilsson and S. Pelger, "A pessimistic estimate of the time required for an eye to evolve" (Proceedings of the Royal Society B, 1994, v.. 256, pp. 53-58)</ref> used computer modeling of the evolution of eyes to find out if it was possible for there to be a smooth gradient of change from a pigmented eye spot to an [[eye]] with a lens and cornea, and how long such a transformation would take. They used highly conservative figures for the possible change in each generation. Many human traits are over 50% heritable, and they gave their model a lower figure. They also chose very conservative values for the amount of possible variation in a population. Using these figures, they calculated that through the mechanism of evolution an eyespot could evolve into an eye with a lens and a cornea in less than a half a million years. | D. E. Nilsson and S. Pelger <ref>D. E. Nilsson and S. Pelger, "A pessimistic estimate of the time required for an eye to evolve" (Proceedings of the Royal Society B, 1994, v.. 256, pp. 53-58)</ref> used computer modeling of the evolution of eyes to find out if it was possible for there to be a smooth gradient of change from a pigmented eye spot to an [[eye]] with a lens and cornea, and how long such a transformation would take. They used highly conservative figures for the possible change in each generation. Many human traits are over 50% heritable, and they gave their model a lower figure. They also chose very conservative values for the amount of possible variation in a population. Using these figures, they calculated that through the mechanism of evolution an eyespot could evolve into an eye with a lens and a cornea in less than a half a million years. | ||
Revision as of 02:48, July 15, 2007
A light-sensitive region in certain protozoa,[1] such as Euglena.
D. E. Nilsson and S. Pelger [2] used computer modeling of the evolution of eyes to find out if it was possible for there to be a smooth gradient of change from a pigmented eye spot to an eye with a lens and cornea, and how long such a transformation would take. They used highly conservative figures for the possible change in each generation. Many human traits are over 50% heritable, and they gave their model a lower figure. They also chose very conservative values for the amount of possible variation in a population. Using these figures, they calculated that through the mechanism of evolution an eyespot could evolve into an eye with a lens and a cornea in less than a half a million years.
This mechanism is contested by Young Earth Creationists, who contend that the Earth was created less than 10,000 years ago, and that in that context such a piece of evolutionary development would not be possible.