Imagine you start an experiment with two vials of flies. One fly vial has 20 flies, the other has 200 flies. After 20 generations of mating, which vial has lost the most alleles across the genome? Has genetic variation increased or decreased within each vial? Has genetic variation increased or decreased between the two vials?
The vial with 20 flies will experience greater sampling error and thus more genetic drift than the vial with 200 flies, so the vial with 20 flies has probably fixed/lost more alleles than the fly vial with 200 individuals. Genetic variation has thus decreased within each population because some alleles have been lost, others fixed.
To determine which vial has lost the most alleles across the genome after 20 generations of mating, you would need to compare the initial genetic variation to the final genetic variation in each vial.
The process to calculate the lost alleles would involve examining the genetic makeup of each vial at the beginning and end of the experiment. This can be accomplished by using various genetic analysis techniques, such as genotyping or DNA sequencing, to identify and compare the alleles present in both vials.
Regarding the increase or decrease in genetic variation within each vial, you would need to assess the overall diversity within the vials at the start and end of the experiment. One way to estimate genetic variation is by calculating the heterozygosity, which measures the proportion of individuals with different alleles at a given genetic locus.
To determine whether genetic variation has increased or decreased between the two vials, you could compare the genetic diversity measurements of both vials at the end of the experiment. By comparing the heterozygosity or other measures of genetic diversity between the two vials, you can assess whether one vial has experienced more or less variation compared to the other.
To obtain the specific results for your experiment, you would need to conduct the appropriate genetic analyses on the fly populations in each vial, collect the necessary data, and compare the results.