Roberts, Richard G. and Jacobs, Zenobia, 2009, Human history written in stone and blood: two bursts of human innovation in southern Africa during the Middle Stone Age may be linked to population growth and early migration off the continent, American Scientist, 97(4), 302-310.
Even by archaeological standards, Blombos Cave is a modestly sized shelter. Yet artefactes recovered from just 13 cubic meters of deposit inside transformed our understanding of when our species developed behavioral attributes we associate with "modern" humans. From this cramped hole in a sandstone cliff on the Southern Cape coast of South Africa, Christopher Henshilwood and his colleagues unearthed evidence of symbolic expression, in the form of abstract designs (carved ochre bars) and personal ornaments (shell beads) at least 70,000 years old. That is more than 35,000 years before anything comparable emerged in Europe.