BIO120H1 Lecture Notes - Lecture 19: Survivorship Curve, Net Reproduction Rate, Exponential Decay
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BIO120H1 Full Course Notes
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Bio120: age-structured populations in life histories (lecture 19) Typical life history for higher plants and animals. When have enough resources, become mature, start spending resources on reproduction. Need to consider age structure of populations to better predict population trajectories and understand paradoxes of evolutionary ecology. Still considering a single population, but now fecundity and survivorship vary with age. Variation summarized by life tables of age-specific rates. If birth and death rates stay constant, pyramid shape is stable, but human rates are always changing. Reflect not all individuals in population the same (potential for death changes with age) Start with a lot of babies, end up with very few older individuals) 2001: top heavy, declining population, not natural (economic factors and birth control) Arbitrary units of time chosen to give a reasonable number of age classes for the organism in question: Humans: typically 5-year intervals, about 20 age classes.
