The Genetic History of Northern Europe - Another Begemoth DNA study on Baltics

[epoch]

what remains is to find out is why depigmentation was favoured by nature

HG's formed a clade from dark (La Brana) to light when going north. That is still the case nowadays, only the distribution of lighter skin has now moved to far lower altitudes. That could be due to higher sensitivity for vitamin D deprivation due to the switch to Neolithic life style

 

[MOESAN]

what if the the mutation was among some megalithers (partly future first genuine BB's?) or these first BB's, both in contact with North Africa, and if one of them (megalithers or BB's) were responsible for the first spreading before positive selection: BBs rovered Atlantic and North Sea from Maghreb to Scandinavia, as did surely some of the megalithers, perhaps spanning a long enough time and not in an eye blink; I avow it's only an hypothesis which doesn't please me too much -

 

[epoch]

what if the the mutation was among some megalithers (partly future first genuine BB's?) or these first BB's, both in contact with North Africa, and if one of them (megalithers or BB's) were responsible for the first spreading before positive selection: BBs rovered Atlantic and North Sea from Maghreb to Scandinavia, as did surely some of the megalithers, perhaps spanning a long enough time and not in an eye blink; I avow it's only an hypothesis which doesn't please me too much -

What the exact vectors were remains to be seen. However, the clear evolutionary pressure for lighter skin means that whatever vector brought the change, the change stuck and expanded.