BIOL 313 Lecture Notes - Lecture 11: Semelparity And Iteroparity, Ruderal Species, Fecundity
4 Feb 2018
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Document Summary
R is a measure of population growth rate. (cid:1688)r selected(cid:1689) species are favoured for increased growth rate, often thought to be important in colonizing new habitats. (cid:1688)k selected(cid:1689) species are likely to have traits that favour efficient utilization of resources, rather than maximizing growth rates. Under certain conditions, selection may favour increases in growth rates. Other circumstances may cause selection for individuals that favour efficient use of resources, rather than maximizing resources. Increased investment in offspring (because will see increased compatibility) Spend ~5 years gathering energy, then use it all at once in reproduction event, then die (big bang effect) Low survival rate of adults between reproductive episodes. High cost of surviving between reproductive episodes. High adult survival rates relative to juvenile survival rates. Characteristic not followed by k-selection: many small offspring. Included environmental conditions to help explain life history strategies in plants. Suggested disturbance and abiotic stress are most important selective pressures, but that competition is also important.
