Communication · c. 3,200 BCE

Writing (cuneiform)

Wedge-shaped marks in clay begin to record speech, and history begins with them.

Sumerian cuneiform grew from accounting signs into a full script that could write names, grammar and eventually literature, law and science. Used for about 3,000 years across more than a dozen languages, it let knowledge, contracts and states outlive any single memory.

See it in the living tree Wikipedia

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 2

What it led to 6

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)

World GDP over a million years Latest: 41k billion 1990 international $ (2000) Source: DeLong 1998, Estimating World GDP, One Million B.C. - Present; Wikipedia: Gross world product (DeLong table, cross-check)

Share of people living in cities Latest: 57.5 % (2025) Source: Our World in Data