Some researchers have indicated a
belief that the I1 lineage had its
roots in northern France, though
there is little evidence for this
argument.[30]
Family Tree DNA continues to
promote this theory.[31]
Genetic remnants remain in northern
France, indicating a small influx of
I1 men, likely during Viking raids
and subsequent settlement.[32]
Subtle increases in I1 haplotypes
indicate a modest contribution,
perhaps from a combination of the
Frankish migration during the last
days of the Roman Empire and later
Viking incursions. Nordtvedt
subscribes to this concept.[33]