Drift increases among-population variance over time
Beginning with a set of populations
where the allele frequency q is
normally distriburted about a mean q
= 0.5, drift will cause the frequency distribution to
flatten. Note that the 0.0 and 1.0 classes act as absorbing barriers:
the distribution is "U" shaped
because alleles frequencies cannot fall outside the interval 0.0 < p < 1.0. Eventually all populations will either
lose
or fix the allele, at which point among-populations genetic variance
will be maximized.
Text material © 2004 by Steven M. Carr
Text material © 2004 by Steven M. Carr