Genetic Drift over time in smaller versus larger populations
From an initial q = 0.50 in each of 10 populations
with N = 20 [top] or 100 [bottom]
individuals, q = f(a) diverges at random over
time from the starting value. The divergence in more rapid
among smaller populations than larger. With N = 20,
eight populations have gone to either loss (q =
0.0) (n = 4) or fixation (q = 1.0) (n =
4) after 100 generations, whereas with N = 100 after
100 generations, all of the populations save one retain both
alleles, in the range of q = 0.01 ~ 0.90.
Allele frequencies continue to vary at random so long as 0 < q < 1: q = 0.0 or 1.0 are absorbing barriers, which once reached end further change. Fate of q in a population is not especially predictable: between g = 70 & 100 with N = 100, dark orange q goes from 0.70 to 0.15, and light green q from 0.10 to 0.80
HOMEWORK: Repeat the simulations with the MatLab program WriFish.m with N = 100 or 1,000 or 10,000 individuals in 10 populations @, over 1,000 generations. Compare the visual variance, as above. Note any loss or fixation events.
Allele frequencies continue to vary at random so long as 0 < q < 1: q = 0.0 or 1.0 are absorbing barriers, which once reached end further change. Fate of q in a population is not especially predictable: between g = 70 & 100 with N = 100, dark orange q goes from 0.70 to 0.15, and light green q from 0.10 to 0.80
HOMEWORK: Repeat the simulations with the MatLab program WriFish.m with N = 100 or 1,000 or 10,000 individuals in 10 populations @, over 1,000 generations. Compare the visual variance, as above. Note any loss or fixation events.