Here in Germany many people trade starters across villages. It would be interesting to have a scientific study on the differences. Maybe there is different bacteria/yeast in the different villages?
Wild yeast is everywhere, and very different from place to place. To my understanding a little jar of one culture stands no chance against the evolutionary pressures outside it, so within a week or two an imported starter will return to whatever yeast exist in that specific area.
Trading across villages would be a really good way to keep 'new' flavours coming in :)