Friday, May 26, 2006

r and K type : what I learned today because I read the comments at

In biology, there are two primary reproduction strategies. (all ref from google search)

The , "r-Type", is far more Darwinian in its approach

Opportunistic ( r-type)

smaller and simpler organisms will favor r - type reproduction ( lots of offspring ) ...

The r type reproductive strategy is basically to pump as much energy and resources .

r type strategy, ie rapid growth, precocious. sexual maturity and short life cycle, .

An r-type organism prefers quick reproduction,

The r-strategy means being very sexually active and having many offspring.


"K-Type" means that the organism should have fewer offspring and put more effort into making sure those children survive.

- the idea is to have as much offspring as possible and the only the strongest will survive.

Equilibrial (K-type)

K-type. (few offspring, expensive care)

The K type strategy involves a large investment of resources in the

k type, with slow growth, late reproduc- ...

For a "K" type population, a certain level of intelligence, coupled with social groupings, is quite advantageous.

The K-strategy means having fewer offspring, but with both mother and father giving them more care.
Humans are the most K strategists of all species.

For our purposes, r is a term in Wilson's equation (Harvard University biologist E.O. Wilson) that stands for the natural rate of reproduction (the number of offspring).

The symbol K stands for the amount of care parents give to insure that their offspring survive.

Plants and animals have different life history strategies. Some are more r and others are relatively more K.

The key for understanding K-selection is the predictability of the environment. Tropical areas like Africa are less predictable because of parasites and sudden droughts. Therefore they select for an r-strategy rather than a K-strategy.

Ann Þ thanks a comment in G

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