title: Balding–Nichols model
text: # Balding–Nichols model
  
  In population genetics, the Balding–Nichols model is a statistical description of the allele frequencies in the components of a sub-divided population. With background allele frequency p the allele frequencies, in sub-populations separated by Wright's $F_{ST}$ F, are distributed according to independent draws from
  
      $B\left({\frac {1-F}{F}}p,{\frac {1-F}{F}}(1-p)\right)$
  
  where B is the Beta distribution. This distribution has mean p and variance Fp(1 – p).
  
  The model is due to David Balding and Richard Nichols and is widely used in the forensic analysis of DNA profiles and in population models for genetic epidemiology.
  
  