1 Basic observations of genetic drift As a start set up driftR with a starting allele frequency of 0 5 zero mutation rate fitness of all three genotypes 1 migration rate 0 number of populations 1 population size 100 and 200 generations Under these conditions only genetic drift should affect allele frequencies Run the simulation Look at the main output window To make this a little less abstract when you think of a opulation please picture a population of your favorite eukaryote So for some of you this will be about xenophyophores or gray whales or California poppies or horseshoe crabs or dumbo octopus Whatever you like a What happens to the frequency of allele A over time Does it always go up Does it always go down What if you run the simulation again And again And again Rather than running it over and over again you could set the number of starting populations to 5 or so Above 5 it gets hard to track each individual population because the graph gets crowded b Is the ending after 200 generations allele frequency in a population the same as the starting allele frequency in that population Or is it always lower Or always higher How would you describe this pattern of change in words c After 200 generations have any populations become fixed for allele A that is p 1 they ve lost allele B or have any populations ever lost allele A p 0 The simulation keeps track of this for you look at the fixed lost counter at the bottom left of the main output window If you run the simulation with the settings above but for 50 populations either run it 10 times with n 5 populations or run it once with number of populations set to 50 what percentage of the populations are left with only one allele A or B d What is the cause of this pattern of change Define genetic drift in your own words