BIOL 1020 Lecture Notes - Lecture 21: Punctuated Equilibrium, Sickle-Cell Disease, Gradualism
15 Mar 2016
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Document Summary
New species form from an original populaion when populaions diverge (gene pools are suiciently diferent) and they can no longer interbreed and produce viable ofspring. Movement to a new locaion far away from the main populaion. Evoluion of several, diversiied new species from one founding species. Isolated from each other by distance of a geographic barrier. Environment is food, temp, chemical composiion of the water: may live near each other but are reproducively isolated. Instantaneous speciaion: polyploid organisms is geneically isolated from both parents. Depends on whether geneics are the same or not. Gradualism: gradual evoluionary process, gradual change over ime. Punctuated equilibrium: sudden changes followed by long periods of litle change. Slow accumulaion of small changes over a long period of ime. People with sickle cell anemia and malaria do beter than those with just sickle cell anemia. Geneic drit: change in allele frequency that occurs due to chance events. Chance events = dramaic climaic / geologic events.
