Biology 1002B Lecture Notes - Lecture 21: Experimental Evolution, Genetic Drift, Mutation Rate
16 Jan 2017
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Most studies of evolution are constrained by two facts. Cant go back in time to examine ancestral forms. Grow e. coli 2,000 generations at 32 or 42 . Expose ancestral bacteria to low ph, observe their grown rate. W= growth rate in evolved strain/growth rate in ancestral strain. Below one ancestor is out preformed. Population size is huge, they are only reproducing by asexual reproduction . 0. 1 ml cells subculture the cells. There is a chance that genetic drift is occurring even though you are transferring 5 mil. If any mutation arise, it is usually due to spontaneous mutation binary fission. Can evolution produce adaptation if it depends on random mutations (most. Every 500 generations (75 days) they would take a sample and freeze it so they always have the ancestor for every line. This enables us to revive ancestral populations and compare them to the evolved populations. 6. 6 generations /day = generation of 3. 63 hours.
