Resolution:
## Figure 2.
Evolutionary model of the demographic history of two groups of populations corresponding
to the Central and Eastern mtDNA evolutionary lineages of the common vole . An ancestral population of size Microtus arvalisN_{A }diverges into the two population groups T_{DIV }generations ago. We assumed a continent-island model for each of the two population
groups. Islands (numbered subscripts) represent populations from which genetic data
is available and the continents (subscripts "Eastern" and "Central") represent collectively
all unsampled populations from a given evolutionary lineage. We further assumed the
population sizes of the continents (N_{Central }and N_{Eastern}) to be large (10^{7 }individuals) and the population sizes of the islands (N, _{1}N, _{2}N, etc.) to follow a Normal distribution with mean _{3}N and standard deviation σ_{N}. Note that only four out of the 11 islands are shown. Backward in time, migration
was only allowed from islands to the continent at rates Nm. While the same demographic model was assumed for both marker types, population sizes
and migration rates were scaled differently (see text).
Wegmann |