BIOL 112 1nd Edition Lecture 7 Outline of Last Lecture I Variation within a population II Variation between a population III Sources of genetic variation a Mutations b Sexual reproduction IV Hardy Weinberg Equation V Application of H W Outline of Current Lecture VI What causes microevolution a Natural selection b Genetic drif c Gene flow d Mutation e Non random mating Current Lecture o 2 Calculating allelic genotypic frequencies from phenotypic frequencies For 1 locus with 2 alleles alleles are p dominant and q recessive P2 homozygous dominant 2pq heterozygous q2 homozygous recessive 1 P2 2pq q2 1 Sum of all genotypic frequencies for gene pool equals 1 P q 1 If q2 is given take the square root of q2 to get q Note a carrier heterozygous individual Carry 1 recessive allele but not expressed because also have dominant allele 2pq Note is the question asking for frequency or What causes microevolution o Natural selection o Genetic drif Sampling error in population These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute Subsequent generations do not show the allele variation of the original gene pool ex Fig 23 8 Bottleneck Fig 23 9 population size dramatically reduces Gene pool is less varied than original gene pool Genetic variability at most loci severely reduced In bottleneck much of population is lost In founder effect original population survives but is separated o Gene flow allele exchange between populations alleles loss or gain reduces genetic differences between populations Migration and successful mating of immigrants Reduces genetic differences between populations o Mutation introduces new alleles o Non random mating
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