BIO120H1 Lecture Notes - Lecture 8: Peppered Moth, Natural Selection, Melanism
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BIO120H1 Full Course Notes
Verified Note
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Document Summary
Orchid from madagascar with long floral tube pollinated by night-flying moth with exceptionally long proboscis - example of co-adaptation. Fitness: relative genetic contribution of individuals to next generation as a result of differences in viability and fertility (darwinian fitness) Selective advantage: some individuals better adapted to the environment and thus have higher fitness. Adaptation: any trait that contributes to fitness by making an organism better able to survive or reproduce in a given environment, or the evolutionary process that leads to the origin and maintenance of such traits. Artificial selection: domesticated plant and animals, genes selected by humans with a purpose. Natural selection: all organisms, selected by abiotic and biotic environment, no purpose. Types of natural selection on quantitative traits. Disruptive selection favors both extremes: leads to character divergence and sometimes speciation, requires spatial heterogeneity or discrete resources. Resistance spreads through the population when cyanide is imposed because there are alleles conferring cyanide resistance found at low frequency in populations.
