BIO120H1 Lecture Notes - Lecture 5: Mutation, Gel Electrophoresis Of Proteins, Balancing Selection
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BIO120H1 Full Course Notes
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Ra fisher, jbs haldane, s wright initiated theoretical population. Foundation for neo-darwinism and the new synthesis . Showed continuous variation, darwinian natural selection consistent with. Demonstrated that evolutionary significance of genetic variation leads to questions and developments in ecological, evolutionary genetics. A) purifying (negative selection) - selection against. Mutations that reduce fitness removed by selection. Important parameters used to measure patterns of genetic variations. Polymorphism (p): proportion of gene loci that are polymorphic. Variability in gene, more than one type of allele. Heterozygosity (h): average frequency of heterozygous individuals per gene locus. Locus: site on chromosome that is usually a gene. Less fit types maintained by repeated mutation: selection maintaining variation. Early evidence for the existence of genetic variation. Selection experiments on quantitative traits in different groups of organisms. Involves controlled breeding and selection of individuals for many generations. E. g. bristle number in fruit flies - drosophila melanogaster. Genetic variation in quantitative genes allows high mean.
