The second phase is categorised, by WEIRD scholars, as the Bronze and (early) Iron Ages, labelling diverse times and cultures by metallurgical innovations.  This period in Europe was characterised by extensive trading networks – bronze in particular needed tin and copper sourced from different locations and there is no reason to believe our travels were unidirectional.[4]

The distribution does, however, suggest a reaching out, possibly based on these new technologies, as far as the British Isles in the West and the Steppe to the East: our migrations were stalled by the power of the Mediterranean civilisations to the South.