This combined with population bottlenecks, the founder effect, mitochondrial mutations and genetic drift will alter the genetic composition of isolated populations, resulting in very distinguishable mutation patterns.
The resulting founder effect and either non-existent or inferior competition resulted in speciation as the lemur ancestors radiated out to fill open or insufficiently guarded niches.
The three smaller founder populations show that one or the other color may predominate (founder effect), due to random sampling of the original population.