Joey37, it may be that in this specific case a Sicilian ancestor could be the most likely vector of the Iberian quota (his grandfather should test himself), as well as a friend of mine - half Sardinian and half Sicilian - has 2.5% of Iberian, but it doesn't always work so in Italy, and you can find some paradoxical situation.
I come from more or less the same areas of FabR1B, but I haven't any sicilian grandfather - that I know they are all local, at least up to all the great-great-grandparents - yet my autosomal of 23andme gives me back 6% of Iberian. Working with a little imagination at this point I could hypothesize the attendance in my family tree of some castilian / navarrians / aragonese military operating between Romagna and the Este Duchy in the early modern age (at the service of Pope Borgia and his sons?), or more recently some French Napoleonic soldier, perhaps from the Languedoc region.It is however a hypothesis that satisfies me only in part, as also in other areas of northern Italy this portion of Iberian tends to appear in a variable but not contemptible manner. A boy from the countryside just outside Piacenza, on the opposite side of the region has 4.2%; my genetic cousin traced with 23and me, originally from Bondeno near Ferrara and from Varese in upper Lombardy, is 3% Iberian.
I therefore think that this component, if it is not traceable in the more recent generations, can sometimes be attributed to more remote influences, perhaps attributable to pre-Roman populations (ancient Ligurian and /or Celtic-Ligurians tribes ...)
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