BIO120H1 Lecture 18: Mon Nov 19 2018
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BIO120H1 Full Course Notes
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Document Summary
Age-structured populations: break population into age classes, life-table parameters, survivorship and fecundity, life histories (trade-offs, cost of reproduction, semelparity vs iteroparity, r vs k strategies) Exponential and logistic models of population growth treat individuals in population the same. Not all individuals have same probability of giving birth or dying. Key components of life history strategies: lifespan, timing of reproduction, # offspring, parental investment. Start life at small size, grow for period without reproducing (resource accumulation), become mature and start spending resources on reproduction (various lifestyles after sexual maturity, some expend all resources at once other spread them out) Need to consider age structure of population to better predict population trajectories and understand paradoxes of evolutionary ecology. Variation summarized by life-tables of age specific rates. Implications for evolution of life histories, conservation of populations, understanding changing structure of human populations (demography) Arbitrary units of time give reasonable # of age classes. Humans: 5 year intervals (so typically 20 age classes)
