Communication · c. 100,000 years ago

Engraved ochre (Blombos)

Geometric patterns cut into red ochre preserve an early tradition of deliberate abstract mark-making.

Ochre pieces from Blombos Cave in South Africa carry engraved patterns from layers about 100,000 to 75,000 years old. A separate silcrete flake bears a drawn crosshatch from about 73,000 years ago. These finds show early Homo sapiens deliberately making abstract designs in several media.

See it in the living tree Wikipedia Source

Arcs above join it to what it stood on, arcs below to what it led to. The bar places this stretch on the tree's whole timeline.

What it built on 1

Spoken language 150k BCE

What it led to 2

Cave art 66k BCE
Tally marks (Lebombo bone) 41k BCE

Related measurements

The dashed line marks when it first worked.

World population over a million years Latest: 6.27k million people (2000) Source: DeLong 1998, table 'Total World Population' (Kremer series); Kremer 1993, Population Growth and Technological Change: One Million B.C. to 1990, QJE 108(3)