Biology 1001A Lecture Notes - Lecture 12: Genotype Frequency, Allele Frequency, Genetic Recombination
23 Mar 2014
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17. 1- variation in natural populations: phenotypic traits exhibit quantitative or qualitative variation within populations of all organisms. These discrete differences are called polymorphisms: genetic variation, environmental factors, or an interaction between the two cause phenotypic variation within populations. Only genetically based phenotypic variation is heritable and subject to evolutionary change: genetic variation arises within populations largely through mutation and genetic recombination. Artificial selection experiments and analyses of protein and dna sequences reveal that most populations include significant genetic variation. Individuals in the population mate randomly with respect to genotypes: under these restrict conditions microevolution will not occur p2+2pq+q2=1. Recessive allele: genotype frequencies in the next generation should reflect (p+q)2: Genotype and allele frequencies: product rule predicts genotype frequencies. If all h-w conditions apply then: 49% crcr, 42% crcw, 9% cwcw p"=(2x490) + (420/2000) = 0. 3: therefore no change from generation to generation, i. e. allele frequencies are constant:
