In fact, following the subdivision of an ancestral population into geographically separated populations, these populations are theoretically expected to go from a polyphyletic stage, through a paraphyletic stage, and eventually to a reciprocally mono phyletic stage with respect to their matriarchical ancestry (compare Figure 11.10 with Figure 11.4, and refer to the definitions of these terms in the glossary) So, with a high rate of mutation rapidly generating new haplotypes, and with a rapid rate of lineage sorting (extinction) of ancestral haplotypes in a population, animal mtDNA will develop a signal of divergence- ultimately reciprocal monophyly-among isolated populations within a much shorter span of time following their initial isolation than is the case for nuclear DNA (Moore 1995). In plants, most phylogeographic studies have used chloroplast DNA rather than mtDNA, and while the overall rate of evolution is much slower than in animal mtDNA, several gene regions are evolving at a relatively rapid rate; thus, the number of studies demonstrating phylogeographic have increased steadily since the advent of PCR-based sequencing methods