Bones and flint tools found in Norfolk and Suffolk show that Homo erectus lived in what is now England around 700,000 years ago.^[16] At this time, England was linked to mainland Europe by a large land bridge. The current position of the English Channel was a large river flowing westwards and fed by tributaries that would later become the Thames and the Seine. This area was greatly depopulated during the period of the last major ice age, as were other regions of the British Isles. In the subsequent recolonisation, after the thawing of the ice, genetic research shows that present-day England was the last area of the British Isles to be repopulated,^[17] circa 13,000 years ago. The migrants arriving during this period contrast with the other of the inhabitants of the British Isles, coming across land from the south east of Europe, whereas earlier arriving inhabitants came north along a coastal route from Iberia. These migrants would later adopt the Celtic culture that came to dominate much of western Europe.