BIO220H1 Lecture Notes - Lecture 7: Demographic Transition, Exponential Growth, Logistic Function
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BIO220H1 Full Course Notes
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Birth + immigration > death and emigration. As n approaches k dn = 0 and the population growth levels off, as n is really small term in the bracket will be close to 1 go back to exponential growth. Population growth rate is a function of the overall density of the individual. Allee predicted 2. 6 billion and logistic growth of the human population. But in reality human population growth is 7. 2 billion and growing exponentially. Extrapolated beyond the range of the data. Logistic growth is not a law, not all species grow logistically (helps explain density dependence: the graph hits the prediction line (asymptote and does not go over, this allows no overshoots, assumes r and k are constant. The intrinsic rate of growth and carrying capacity are not changing. The alternative scenarios: the populations are allowed to overshoot, overshooting and whether density dependence occurs instantaneously but with a time lag.
