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Unformatted text preview: side of the
equation nears zero.
As population size increases, logistic growth rate
becomes a small fraction of growth rate.
Highest when N=K/2.
N/K = Environmental resistance. 1 9/25/11 Logistic Population Growth Logistic Population Growth What causes the rate r to change? Limits to Population Growth
Environment limits population growth by
altering birth and death rates.
Resource competition, Predation, Disease Density-independent factors
Natural disasters Density Independent Factors
-Galapagos Finch Population Growth- Density Independent Factors
-Galapagos Finch Population Growth Boag and Grant (1984) - Geospiza
fortis was numerically dominant
After drought of 1977, population
fell to (180).
Access to food
1983 - 10x normal rainfall Density Independent Factors
-Galapagos Finch Population Growth- 2 9/25/11 Cactus Finches and Cactus Reproduction Cactus Finches and Cactus Reproduction Grant and Grant documented several
ways finches utilized cacti: Finches t...
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This document was uploaded on 03/19/2014 for the course BIO 250 at Xavier.
- Fall '13