>non-breeding, though genetically connected, "end" populations may co-exist in the same region This reminds me of the Riemann surface associated with the compl

>non-breeding, though genetically connected, "end" populations may co-exist in the same region This reminds me of the Riemann surface associated with the complex logarithm: https://en.wikipedia.org/wiki/Complex_logarithm#The_associated_Riemann_surface https://en.wikipedia.org/wiki/Complex_logarithm#The_associat...