All ultimately intermarried to produce a race of many strains, which may account for the paradox that a people famed for stolid, patient, practical common-sense; a nation as Napoleon said, of "shopkeepers", has produced more adventurers, explorers and poets than probably any other in history.
When we encounter new details of our world we fill in more of the spaces. When we discover details that don't seem to fit with our view of the world, we have a kind of "crisis of faith," even if our worldview is not especially religious. We're forced to redraw our "map" a bit.