Dawn...
For the first part... the 3D graph, look at figures 10.6 and 12.21 in the text.
for 10.6:
type I (k-selection)
-high juvenile survival
-high mortality among older individuals
-low fecundity(# of eggs or offspring) - higher parental investment
-later age at first reproduction
type II (uncommon)
-mortality at equal rates among age ditribution
type III (r-selection)
-high juvenile mortality rate
-lower mortality among older individuals
-high fecundity
-earlier age at first reproduction
for 12.21:
periodic
-low juvenile survivorship, high fecundity, and late age at first reproduction
-also allocates resources to reproduction
equilibrium
-high juvenile survival, low fecundity, and late age at first reproduction
-allocation to reproduction is low
opportunistic
-low juvenile survivorship, low fecundity, and early age first reproduction
-allocation to reproduction is also high
There is a direct correlation between the equilibrium life history
(tradeoff) in the 3D graph and type I survivorship (k-selection). the other
survivorships do not fit a "corner" perfectly, but they do fit onto a curve of
the bubble. Also realize that the survivorship curves (10.6) are a dated
(1960s) interpretation, whereas the tradeoff/life history graph (12.21) is an
updated "new" look at survivorship.
2nd part
r-selection, or type III survivorship, is a pattern of survival that allocates a
species' resources to reproductive output. it is characterized by reproduction
at an early age and a one-time reproduction event. a large portion of the
organism's biomass is dedicated to reproduction... think of examples like
ragweed that disperse 1,200 seeds/individual, or frogs and inscets that invest
energy into the # of offspring rather than energy into rearing each individual
offspring.
hope some of this helped...
-matt
Quoting Dawn Maura Shackleton <[log in to unmask]>:
> On the new 3D trade off model is the r-selection suppose to be on the
> "survival"
> axis and the k-selection suppose to be on the "age at maturity" axis, or is
> that just the way I drew it? Do they rotate around the "bubble"? Lastly,
> could someone give me a short consise explaination of r-selection. Is it
> just
> population growth relative to instantaneous per capita changes?
>
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