and given that
Ne for nuclear loci is approximately four times Ne for
mitochondrial loci, mitochondrial and nuclear markers
are informative about demographic and dispersal
structure in the intermediate (mtDNA) and distant
(nuDNA) past. Traits under directional selection sweep
to fixation much more rapidly than neutral lineages
coalesce (i.e., independent of population size); hence
they may identify relatively recent barriers to gene
flow