BIOB51H3 Lecture Notes - Lecture 23: Drosophila Melanogaster, Inbreeding Depression, Cdk5R1
16 Apr 2016
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Document Summary
Increase or decrease p35 expression: increase = increase rate of cell death decrease = decease rate of cell death. Even if aging is due to accumulation of damage, we are still left with questions: Evolutionary hypothesis of aging: aging caused by the failure of organisms to completely repair cell and tissue damage failure to completely repair damage due to mutation-accumulation and trade-offs between repair and reproduction. Mutation-accumulation: weak selection against deleterious mutations whose negative effects occur late in life. Trade-offs between repair and reproduction: selection in favour of mutations with positive effects early in life, but negative effects late in life. Fraction surviving: fraction surviving at previous age * annual survival rate. Expected rs (reproductive success): fraction surviving * rs of survivors. Mutation-accumulation hypothesis: deleterious mutations that cause cell/tissue damage accumulate in a species" genome over evolutionary time: if negative effects come late in life, selection is too weak to eliminate these mutations.
