Aging

Question 1

What is Aging

Answer 1

progressive decline in somatic function reflected in reductions in fertility and surviourship

Question 2

proximate cause of aging

Answer 2

progressive degeration of the soma
impaired function and increased disease

Question 3

Costs of reproduction in terms of aging

Answer 3

• trade offs may govern the evolution of DNA repair mechanisms so high reproductive rates will accelerate senscence (aging) and therefore shorten lifespan

Question 4

Evolutionary theories of aging

Answer 4

1. Mutation Accumulation
2. Antagonist Pleiotropy

Question 5

Mutation Accumulation

Answer 5

• Few survive to older age and those that do are likely to have already reprodcued
• strength of selection declines with age
• mutations with late life deleterious effects accumulate in genome of species over time because they are not under strong selection

ex: single gene effects

depends on fact that strength for/against trait declines with age at which that trait is expressed

Question 6

antagonist pleiotropy

Answer 6

mutations/genes with beneficial effects early in life may be favoured even if those mutations have negative effects late in life
- few survive to old age and if they do they already reproduced
- strength of selection declines with age

depends on fact that strength for/against trait declines with age at which that trait is expressed

Question 7

reproductive value

Answer 7

expected contribution of offspring to future generations of individuals of age x
high during early life and low during late life

Question 8

the strength of natural selection depends on the differential reproductive success of

Answer 8

genes

Question 9

Reproductive value of early life deleterious (A) , neutral (B) and late-life deleterious muations (C)

comparisons

Answer 9

Early Life: A is low, B and C is high. (Big difference between A and B+C)
Late Life: no A, low B and C
Difference between reproductive value of B and C is small