Tools & manufacturing · c. 48,000 years ago

Ground stone axes

Grinding stone against stone gives a tough, durable edge.

Edge-ground axes appear in northern Australia by about 46,000 years ago and become the signature tool of Neolithic farmers. Polished axes cleared forests for agriculture.

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 1

Acheulean hand axe 1.8M years ago

What it led to 2

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)