@jillholl @cdarwin
We all originate from a human species originally only native to Africa. Even the Native Americans migrated - though to a place where no other humans lived at that time. But their Asian ancestors encountered another human species in Europe and Asia: the Neanderthal.
Migration lies in human nature and is quite common - so common that it is hard to find indigenous Europeans (like the SĂ mi, for instance). Worldwide, only 350 million people are still indigenous - less than 4.5 %.