BIO120H1 Lecture Notes - Lecture 5: Selective Breeding, Heterozygote Advantage, Population Genetics
36
BIO120H1 Full Course Notes
Verified Note
36 documents
Document Summary
1930 50 theoretical population genetics was initiated by fisher haldane and wright and provided the foundations for neo darwinism and the new synthesis. They showed that continuous variation and darwinian natural selection were entirely consistent with mendel"s laws. Important parameters used to measure patterns of genetic variation: polymorphism (p) Proportion of gene loci that are polymorphic: heterozygosity (h) Average frequency of heterozygous individuals per gene locus ( a site on a. Processes that influence patterns of genetic diversity chromosome that is usually a gene: mutation (increase diversity) Caused by random errors during replication: recombination (increase diversity) Introduces new combinations of mutations into a population. Get it by sex: random genetic drift (decrease diversity) Drift important when populations become small: natural selection (increase/decrease diversity) Mutations that reduce fitness removed by selection. Natural selection maintains diversity: e. g. heterozygote advantage, many controversies in evolutionary biology concern the relative importance of these forces in evolution. Absence of genetic variability prevents artificial selection.
