R/K selection theory
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The r/K selection theory is an evolutionary hypothesis examining the selection of traits in an organism that trade off between quantity and quality of offspring. Species which produce more offspring a
North Atlantic right whale with solitary calf. Whale reproduction follows K-selection strategy, with few offspring, long gestation, long parental care, and a long period until sexual maturity.
A litter of rats with their mother. The reproduction of rats follows an r-selection strategy, with many offspring, short gestation, less parental care, and a short time until sexual maturity. The same applies to mice.
A bald eagle, an individual of a typical K-strategist species. K-strategists have longer life expectancies, produce fewer offspring, and when young tend to be altricial, require extensive care by parents.
Survivorship curve
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A survivorship curve is a graph showing the number or proportion of individuals surviving to each age for a given species or group. Survivorship curves can be constructed for a given cohort based on a
R/K selection theory
…Semelparity and iteroparity Survivorship curve Trivers–Willard hypothesis…
An illustration of the three idealized types of curve (logarithmic scale)