Unformatted text preview: Population Genetics and Human Evolution
Chapter 19 Population = Gene pool = Populations as Genetic Reservoirs Allelic frequency = Distribution of Humans Fig. 19.1 Allelic Frequencies How can we determine the % of alleles in a population? HardyWeinberg equation HardyWeinberg Law What are the assumptions of this model? Large population No selection; all genotypes survive and reproduce equally Random mating No mutation or migration HardyWeinberg Law p2 represents..... q2 represents..... 2pq represents..... Frequency of Heterozygous Traits Changing Allelic Frequencies Genetic drift = Founder effects = Natural selection = Mutations Generate New Alleles Mutation has little effect on genetic variation in a pop. Allele frequency determined by: genetic drift, migration, and selection Selection and Gene Frequecies Sickle cell disease & malaria Heterozygotes have survival advantage Prevents allele from disappearing Distribution of Sickle Cell Anemia and Malaria Fig. 19.9 Genetic Diversity Genetically, are there races? Inside a population = high genetic variation Between populations (i.e. races) = little genetic variation Race does not exist to geneticists Genetic Variation
The variation within a population is greater than the variation between populations
Fig. 19.11 Where did we come from? How did humans move throughout history? Data from: anthropology, paleontology, archaeology, and genetics North and South America populated by migrations 15,000 or 30,000 years Appearance and Spread of Homo sapiens Fig. 19.12 ...
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