Iain Davidson, an Australian rock art specialist at the University of New England in Armidale, New South Wales, has suggested that marking ownership must have come after humans became self-aware. via Oldest ‘writing’ found on 60,000-year-old eggshells — life — 03 March 2010 — New Scientist. Take that communists!
Oldest ‘writing’ found on 60,000-year-old eggshells