It depends on what consequences one draws from those links. Megalithism was mostly carried out by neolithic farmers* rather than Bronze age peoples with steppe ancestry, so these early links might not have translated into anything game changing from a population-wide perspective. In Britain the farmers were virtually wiped out, and with Bell Beaker migrations the megalithic phenomena died out around here. This isn't to say that were were no contacts, or that no one ever moved here, but I simply do not believe that translated into a clear increase in steppe ancestry in W Iberia. I used to consider that hypothesis in the past (Atlantic Bronze Age migration from Britain/NW France into Iberia), but the more pre-historic samples we have, the less I believe it had a genetic impact. If new significant samples show different info, I'll review its consequences and update my beliefs accordingly.
In the end I follow the mantra "the past explains the present, it's not the present that explains the past".
As for north Africa I'm just not familiar with the connections besides the odd ivory item, or the occasional migrant. I do also find it (pleasantly) surprising to see it so widespread in Lisbon by the late Roman period, maybe the migration/forced movement had to do with mining operations in Hispania? I really want to see Late Roman samples from Braga or Lugo since, in theory, that's where the core of Galicia-Portugal was in the early Reconquista. Soil acidity might make that a mirage for now.
* And speaking of neolithic farmers, here's an interesting paper on the subject, and why we benefit so much from Iberia_N references instead of LBK like most Europeans do. As usual EEF stuff gets ignored because most people in these forums have a hard on for steppe and indo-europeans.
https://www.sciencedirect.com/scienc...60982222007059
