One effect of inbreeding is to increase the frequency of homozygotes (and thus, necessarily, decrease the frequency of heterozygotes). Note: while the frequency of genotypes change with inbreeding, the frequencies of alleles remains the same (assuming no selection, migration, mutation). Refer back to the data table presented on page 2 of Lecture 6 to convince yourself that those data could be a result of inbreeding: F=(0.343 - 0.14)/0.343 = 0.59. When the allele frequency is not zero, but there is a complete absence of heterozygotes , F = 1. As an exercise, work through the data in table 5.2, pg.98. Does this illustrate high or low inbreeding? Genetic variation is generally "lost" by the action of genetic drift. This is true if we follow the fate of one deme over time. Note, however, that in our array of populations, variation is "lost" within demes, but the variation in the total system is preserved, i.e., the allele frequency in the entire metapopulation does not change, only the genotype
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