Aging and Life History
Last Modified: 2011-07-16
-Reduces and individual's fitness
*Should be opposed by Natural Selection
-Bats live 3x as long as other mammals of same size and similar metabolic rates.
-Boosting telomerase expression.
-The physiological and genetic mechanisms for longer life already exist.
-Pleiotropic genes with benefits early in life and costs late in life.
-Confirmed by Hughes in pattern of fruit flies.
-Caused late acting mutations to become neutral.
-Longevity declined rapidly, in both large and small populations.
-Half of natural possum deaths are caused by predators.
-Sapelo Island has NO mammalian predators.
*Sidenote: Second year mainland female offspring grow more slowly than first year.
: Second year island female offspring grow just as fast as first year.
2. Reproductive performance.
3. Connective tissue physiology.
2. Increases breaking time.
*Menopause is a life history adaptation associated with the contribution grandmothers make to feeding their grandchildren.
(1) Daughters of helpful grandmother have more children.
(2) Helpful grandmothers achieve higher fitness.
1. How many offspring are produced at one time.
2. How much time and energy parents can provide to each offspring.
-Number of surviving offspring reaches max at intermediate clutch size. (Favored by selection)
** (# surviving offspring) = (clutch size) x (probability of survival)
2. Its survival or reproductive performance in future years.
** Evidence found a (1) trade-off between current and future reproduction (2) trade-off between current reproduction and future survival.
-When eggs were added, daughters produced smaller clutches.
2. ***Reproductive Performance***
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