BIO120H1 Lecture Notes - Lecture 19: The Breakthrough, Michael Majerus, Kettlewell
36
BIO120H1 Full Course Notes
Verified Note
36 documents
Document Summary
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 (noun). (verb) the evolutionary process that leads to the origin and maintenance of such traits. Domesticated plants and animals; selection experiments in genetics. All organisms, selection by abiotic & biotic environment, no purpose or goal; a blind mechanistic process that just happens. Stabilizing selection: natural selection stops the genes from changing and stabilizes on average traits. E. g. , stabilizing selection on human birth weight. If a baby is born too light (can"t survive) and too heavy (loss of maternal parent). Directional selection: favours one extreme, and goes into that direction when evolving. E. g. , beak size in galapagos finches, as the seed abundance decreased, the population fell.
