D. Population size and the rate of genetic drift: A common rule of thumb in conservation biology (Franklin 1980) is that a population size of at least 500 is needed to preserve genetic variability, so that the population can respond to future changes in environmental conditions. Recently, Lande (1996) argued that a population size of 5000 is a more realistic target. To test these ideas, compare changes over time in two populations that are of different size, but are otherwise the same. How will changes in genotype frequencies through time differ between the two populations? Allele frequencies? How will the final frequency distribution for allele frequencies differ for the two populations? Does either population actually lose genetic variability? Does the length of time that passes affect the likelihood that an allele will become fixed (that is, hit a frequency of 0 or 1)?