"It reports that sea level rises and cold climates intervened to push pioneering groups of humans out again and again until our ancestors were finally established some 12,000 years ago."

I wonder if the word finally is misplaced there. During the next glacial period, the area may become uninhabitable again. In those past 700k years they talk about, there may have been periods much longer than 12k years that the area was inhabited. Each of those previous 7 settlement attempts would probably have seemed like the finally successful attempt to the people at the time.