BIOC51H3 Lecture : BGYB51H3 Lecture 23 Notes Nov 26
11 Aug 2010
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BGYB51H3 Lecture 23 Notes
-evolutionary hypothesis of aging says that aging is caused by failure organisms to completely
repair cell and tissue damage
-there is weak selection against mutations on older organisms
-positive early effect on reproduction is favoured by natural selection and usually outweighs
negative effects
-mutation accumulation hypothesis and repair-reproduction trade off hypothesis are part of
the evolutionary hypothesis of aging
-mutations that decrease the ability of organism to maintain body in good repair are evident as
the organism ages
-uµZ}v[((o](]u}µ]ÀµZuµZ](}µ]}v}µ
early in life
-mutations may be maintained through mutation-selection balance if selection is weak during
late years
-deleterious mutations early in life are eliminated
-repair-reproduction hypothesis is the antagonistic pleiotropic hypothesis
-mutations that increase lifespan lead to decreased early reproduction (vice versa)
-reproducing early comes with the cost of less offspring compared to late reproduction
-early reproduction causes increased senescence when adding eggs to the nest
-ecological mortality is mortality caused by extrinsic factors
-senescence is changes in function caused by intrinsic factors
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Document Summary
Evolutionary hypothesis of aging says that aging is caused by failure organisms to completely repair cell and tissue damage. There is weak selection against mutations on older organisms. Positive early effect on reproduction is favoured by natural selection and usually outweighs negative effects. Mutation accumulation hypothesis and repair-reproduction trade off hypothesis are part of the evolutionary hypothesis of aging. Mutations that decrease the ability of organism to maintain body in good repair are evident as the organism ages. Mutations may be maintained through mutation-selection balance if selection is weak during late years. Mutations that increase lifespan lead to decreased early reproduction (vice versa) Reproducing early comes with the cost of less offspring compared to late reproduction. Early reproduction causes increased senescence when adding eggs to the nest. Ecological mortality is mortality caused by extrinsic factors.
