Wright-Fisher model
From the Wright-Fisher model of genetic drift, the random sampling of allele from one generation to the next is taken from a binomial distribution with parameters $2N$ and $p$, where $N$ is the population size and $p$ the frequency of an allele of interest.
Strength of Genetic drift
The strength of genetic drift can be measured in terms of two different statistics:
- variance in allele frequency from one generation to the next
- loss of heterozygosity per generation
Variance in allele frequency from one generation to the next
From the above, it is relatelively straight forward to show that the variance in allele frequency in the successive generation is
$$\text{var}\left(p'\right) = \frac{p(1-p)}{2N}$$
, where $N$ is the population size.
Loss of heterozygosity
Heterozygosity decays by $1-\frac{1}{2N}$ every generation
$$H_t = H_{t-1}\left(1-\frac{1}{2N}\right)$$
, where $H_t$, is the expected heterozygosity at time $t$.
Source
See Gillespie: Population Genetics - A concise guide chapter 2 for more info on these predictions.
Question
Do we have empirical evidence that the decay rate in heterozygosity and/or the variance in allele frequency due to genetic drift follows these predictions?
