Wahlund Effect and F-statistics

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Instructions

• Select a set of allele frequencies (default: p=0.90 0.70 0.50 0.30 0.10)
• Select an inbreeding coefficient within populations (default: f=0.0)
• The display is updated automatically updated after each selection

Interpreting the results

Genotype frequencies within each population are calculated according to the standard formulas:

freq(AA)=p²(1-f) + pf
freq(Aa)=2p(1-p)(1-f)
freq(Aa)=(1-p)²(1-f) + (1-p)f

Expected frequencies across the sample of populations are calculated according to Hardy-Weinberg expectations using the average allele frequency, i.e.

freq(AA)=P²
freq(Aa)=2P(1-P)
freq(aa)=(1-P)²

where

P=sum(p_i)/n .

Observed genotype frequencies across the sample of populations are calculated from the average genotype frequency across populations.

F_is = f (from the listbox above)
F_st = Var(p)/P(1-P)
1-F_it = (1-F_is)(1-F_st)

where

Var(p) = sum(p_i - P)²/n .

Remember that F_it is also equal to

1 - (obs. heterozygosity)/(2P(1-P))