Nowadays R1b is very common is Spain, like 70-75%. And it's domestic(Basque origin) downstream DF-27 makes like 40%.
But here's the thing, during al-Andalus times most haplogroups were Berber/Arabic. So we have to assume a population substitution.
We have to take into account that war is very normal and events and conquests that we summarize a lot, actually take centuries to develop, so there's plenty of room for genocide in large scale.
Something that left me wandering: What is the point to even ask what is the amount of Roman or Celtic DNA?
If the most likely explanation is that today we only see a handful of the lineages that once existed.
Hardly surprising for someone who studies population genetics and its history.
But here's the thing, during al-Andalus times most haplogroups were Berber/Arabic. So we have to assume a population substitution.
We have to take into account that war is very normal and events and conquests that we summarize a lot, actually take centuries to develop, so there's plenty of room for genocide in large scale.
Something that left me wandering: What is the point to even ask what is the amount of Roman or Celtic DNA?
If the most likely explanation is that today we only see a handful of the lineages that once existed.
Hardly surprising for someone who studies population genetics and its history.