BIO 2129 Lecture Notes - Lecture 10: Fecundity, Exponential Growth, Genetic Drift
8 Oct 2016
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Document Summary
Extinctions are rare can happen under natural circumstance, but rates are low. Populations which are very dense are likely to shrink, (due to exceeding k) Birth and death rates vary as a function of density. Mortality rates: if you start off with small numbers, you will end up with numbers similar to what you have started with. Why: resource competition a resource is insufficient to enable high population br or low dr, disease. Individual contact more frequent thus infections spread: interference of competition (aggression) Population density approaches stable values which is associated with logistic growth: logistic population growth (obviously not exponential) In inverse density dependence: populations which are small and quickly decline into extinctions the allee effect. Due to low genetic diversity (imbreeding or genetic drift) Failure to find a mate with low densities: populations which are large which may show exponential growth.
