Originally Posted by
Jackson
I think in this calculator it is broader. It certainly seems to have spread with Germanics but to have been something else before-hand if i had to guess based on the evidence. Like I1 - It has a heavy distribution in some decidedly non-Germanic areas, but also in Germanic areas. Perhaps it is related to either the closeness of Balto-Slavic to Germanic, or to the non-IE words (for example) in Germanic?
Again it's certainly not a 100% correlation, it's disproportionately high in the British Isles where I1 doesn't regularly exceed 15-20%, and also Ireland where it doesn't seem to exceed 5-10%.