BISC 300 Lecture Notes - Lecture 6: Frequency-Dependent Selection, Allele Frequency, Selection Coefficient
24 Jun 2020
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Document Summary
Understand how to calculate hardy weinberg equilibrium to test if a population is conforming to it. Differentiate between average and relative fitness, and understand how to calculate average fitness. Explain how heterozygote advantage, frequency dependent selection and mosaic evolution promote genetic variation. Colors denote how strong selection is on the organism. New recessive a allele selection is much slower compared to a new dominant a allele selection. New dominant mutations increase in frequency rapidly (are seen phenotypically which masks recessive allele) Approach fixation slowly (selection against rare recessive is slow because recessive alleles they"re hidden) Reason why diseases in humans are difficult to get rid of (hidden) New recessive mutations increase very slowly in frequency (rarely exposed in homozygous form) Once common, recessive alleles approach fixation quickly (selection against deleterious dominant is fast) So far, we have considered selection as leading to alleles fixing in a population: this decreases genetic variation.
