poe_population_01[1]

poe_population_01[1] - this is a big deal • Geometric and...

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Population Ecology Population Growth Population Genetics Population Structure

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Population Growth • Geometric Growth – Reproduction in discrete steps • Exponential Growth – Reproduction is continuous • Compound Interest Rate • A population: – Endangered; able to persist; spreading…
Population Bomb • Key Assumption - Growth rate is density-independent • Population growth rate: is r [R]= b - d – b = birth rate – d = death rate • If b = 10 and d = 2; r = 10 - 2 or 8 • If b = 5 and d = 8; r = 5 - 8 or -3 • If b = 10 and d = 10; r = 10 - 10 or 0

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Population Bomb- Continuous • So the intrinsic rate of increase is N t = rN
Geometric Growth t N = t R 0 N

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t N = 0 N rt e Exponential Growth
t N = 0 N rt e t N = t R 0 N

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Geometric vs Exponential time N
Growth r = ?

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Growth r = ? r = ?
Growth r = ? r = ? r = ?

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So…? • Here, distinction between geometric and exponential growth…mostly a pain • BUT--when we look at density dependence…

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Unformatted text preview: this is a big deal • Geometric and exponential growth are Linear Processes : an N is never multiplied by another N: N 2 is a Non-Linear Process But in the “Real World” • Stuff happens -why are we not hip deep in bacteria? • A number of reasons • • environmental stochasticity (random stuff) that affects “r” • BIG DEAL ! t + 1 N = t N + r * t N * K − t N K ⎛ ⎝ ⎜ ⎞ ⎠ ⎟ Logistic Growth Time N K r and K Selection • r-selection - density independent – High growth rate – Many offspring; most do not make it – Large population fluctuations • K-Selection - density dependent – Low growth rate – Few offspring – Population at carrying capacity r and K • Simplification- • Continuum • Nice generalization • Equal Payoff r-selected spawners Flood the environment K selected Sorry…...
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This note was uploaded on 09/15/2011 for the course BIOL 313 taught by Professor Staff during the Spring '11 term at S.F. State.

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poe_population_01[1] - this is a big deal • Geometric and...

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