The map for 300-700 AD shows immigration from the direction of Gallia and Britannia, not Central Europe:
See the blue arrow, which shows North-Western (rather than just northern) source of the bulk of this shift:
Looks like after the loss of Eastern provinces, people from Western provinces started migrating to Rome.
We are talking mostly about immigrants who were citizens of the Roman Empire, rather than barbarians.
Perhaps it included Roman citizens evacuated from Britain to Italy:
https://www.jstor.org/stable/297204
Yes, well I'm not sure I buy their explanation, and nor does Razib Khan.
Rome was Ground Zero for looting, destruction etc. This was when Rome was sacked and plundered. People scattered. The capital of what was left of "Rome" in Italy was moved to Ravenna. Why the hell would people head toward it at that point in time?
People can't just speculate wildly while knowing nothing of what was going on historically.
The Gothic War raged in Italy between 376-382. Before people start with the Goths again, there weren't very many of them, there didn't need to be, what with the plague also raging.
[TABLE="class: wikitable, width: 100%"]
[TR]
[TD]
382[/TD]
[TD]3 October[/TD]
[TD]
Gothic War (376–382): The
Goths were made
foederati of Rome and granted land and autonomy in
Thrace, ending the war.[/TD]
[/TR]
[/TABLE]
[TABLE="class: wikitable, width: 100%"]
[TR]
[TD]
402[/TD]
[TD][/TD]
[TD]The capital of the
Western Roman Empire was moved to
Ravenna.[/TD]
[/TR]
[/TABLE]
[TABLE="class: wikitable, width: 100%"]
[TR]
[TD]
410[/TD]
[TD]24 August[/TD]
[TD]
Sack of Rome (410):
Rome was sacked by the
Visigoths under their
king Alaric I.[/TD]
[/TR]
[TR]
[/TR]
[/TABLE]
[TABLE="class: wikitable, width: 100%"]
[TR]
[TD]
455[/TD]
[TD]16 March[/TD]
[TD]
Valentinian III was assassinated on orders of the
senator Petronius Maximus.[/TD]
[/TR]
[TR]
[TD]17 March[/TD]
[TD]The
Senate acclaimed
Maximus augustus of the
Western Roman Empire.[/TD]
[/TR]
[TR]
[TD]31 May[/TD]
[TD]
Maximus was killed by a mob as he attempted to flee
Rome in the face of a
Vandal advance.[/TD]
[/TR]
[TR]
[TD]2 June[/TD]
[TD]
Sack of Rome (455): The
Vandals entered and began to sack
Rome.[/TD]
[/TR]
[/TABLE]
In succeeding periods Byzantium caused the shots, and the Lombards and Byzantines battled all over Italy.
Please tell me how the authors could imagine that civilians from northwestern Europe were heading toward Rome to settle?
I'm honestly trying to keep an open mind about this, but it makes no sense.
If they're talking about soldiers of Germanic ancestry, i.e. Goths, Vandals, and Lombards, you'd need a lot of their yDna to affect such big changes, and it's just not there, other than in a few pockets easily accounted for by drift in some individual locations. THat's why the R1b in my area of Italy is over 70%, by the way, although the autosomal analysis tells a different tale.
I'll go back to Ralph and Coop. Based on IBD analysis, they found no signficiant "foreign" input into modern Italians after about 500 BC, which, I'll remind everyone is the Iron Age, hence Khan's hypothesis of how the area was re-settled.
If anything, this is a movement of people from more northern and northwestern parts of Italy toward the center and south.
Find a better theory based on knowledge of Roman history and I'll be glad to entertain it.