Regarding Iberia, what are everyone's opinions on R1b's initial presence there?
Well you know my view - Copper Age. I see R1b moving up the Danube to the Carpathian Basin, splitting up along the way, with some people moving into Illyria and others (The Stelae People) through Illyria to Northern Italy and then taking the coastal route to Iberia. Another route led out of the Carpathian Basin to the head of the Danube, settling north of the Alps. Both routes eventually led to the British Isles, but L21 appears to be on the overland route, don't you think?
There is Bell Beaker material in Morocco
. I don't have a date for it, but Bell Beaker is of course later than the first arrival of copper technology in Iberia, so presumably it represents exploration across the Strait of Gibraltar long after the first arrival in Iberia.
I agree about L21 being an overland expansion. It looks like whatever R1b arrived in Iberia, some of them left not too long after to re-expand to the north and east. All of the new snp's under L11 seem to coincide with Desideri's dental studies showing an expansion out of Iberia with return to the east. L21 may be linked with the northern Atlantic based movements.