BIOL 2030 Lecture Notes - Lecture 12: Human Genetic Variation, Genotype Frequency, Allele Frequency
13 Feb 2016
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Document Summary
Population genetics: the sub-discipline of genetics devoted to assessing the genetic variation in populations and explaining its origins, maintenance, and functional significance. Take samples of large populations to determine. Allelic frequencies genotypic frequency of whole pop: frequencies of different alleles in a population. More useful in determining variation than genotype frequencies as alleles are what are passed between generations: methods to calculate allele frequencies: Allelic frequencies can be derived from genotype frequencies but genotype frequencies cannot be derived from allelic frequencies: calculation of allele frequencies from genotype numbers. Freq of allele a, f(a) = 22/40 = 0. 55. Freq of allele a, f(a) = 18/40 = 0. 45. Naa = number of individuals of a particular genotype (e. g. aa) N = total number of individuals in a population. 3 alleles (a1, a2, a3) at a locus in a population of 100 diploid individuals: genotypes: a1a1 = 40; a1a2 = 10; a2a2. = 20; a1a3 = 8; a2a3 = 6; a3a3 = 16.
