A long view of globalisation in short: The humanisation of the globe, part 2 of 5

Richard Baldwin 27 November 2018

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This blog post looks at the first of four phases of globalisation in more detail – the phase I call ‘humanisation of the globe’. The human race began in one geographical area, Africa, where it stayed for over a hundred thousand years before starting to spread outward. However, the expansion of humans around the globe didn’t happen suddenly – it took millennia.

Homo sapiens emerged roughly 200,000 years ago (or maybe 300,000).  Early humans were foragers, not producing much of anything, eating what nature afforded, where they could find it. That suggests migration. And it wasn’t long before mankind began to chase resources around the world.  

Four major waves of migration took the human race outside Africa. Researchers led by a teamfrom the University of Hawaii at Manoa identified four spurts of migration, that took place:

  • 106,000–94,000 years ago,
  • 89,000–73,000 years ago,
  • 59,000–47,000 years ago, and
  • 45,000–29,000 years ago.

Migration was fitful because it was interrupted by intervals of extreme climate changethat created, alternately, sheets of ice and impassable deserts, both of which kept people where they were (Figure 1).

Figure 1 Climate change since the first Homo sapiens

Source: Author’s elaboration of data from Jouze et al. (2007); based on Arctic Dome C ice cores.

Archaeological evidence shows the first migration left Africa by crossing what is now Egypt and entered the Fertile Crescent, but DNA evidence tells us that they did not survive. The next two migrations didn't do any better. (Note: If you like this stuff, you’ll love Who We Are and How We Got Here, a new book by David Reich; he leads a team of molecular biologists, computer scientists, mathematicians, archaeologists, and geneticists at Harvard University that is discovering all sorts of unexpected facts about ancient human migrations.)  

Only the last migration succeeded. Leaving Africa by the Red Sea route, a few thousand humans spread out across the Arabian Peninsula and the Levant – and then spread out to everywhere else too. As Reich writes: “The take-home message is that modern human people today outside of Africa are descended from a single founding population almost completely.” 

As shown in the map below, the humanisation of the globe happened over tens of thousands of years. By about 12,000 years ago, all the habitable bits of land were inhabited. (And all other humanoids, like Homo erectusand Neanderthal, were extinct.) 

Figure 2 Globalisation of the human race

Source: Dates of earliest continuous settlement based on contemporary DNA (author’s elaboration from mitomap.org).

Populations went to places with climates that provided plenty of vegetation and other needs. Production meant altering plants and animal products to make tools that allowed us to get enough nourishment to survive long enough to reproduce. Most humans moved to a food source, exhausted it, and then moved on to another. Trade in food, or really anything, was rare, because transporting it was primitive and slow. 

There are always exceptions, though. We dohave evidence of trade in … rocks. Specifically, obsidian – a form of volcanic glass that made cutting edges – was traded among nomads in the area of the Middle East known as the fertile crescent.

In the next post, we’ll see the effects of the agricultural revolution on globalisation.

References

Reich, D (2018), Who We Are and How We Got Here: Ancient DNA and the New Science of the Human Past, Pantheon

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Topics:  Economic history Migration

Tags:  globalisation, early humans, migration

Professor of International Economics at The Graduate Institute, Geneva; Founder & Editor-in-Chief of VoxEU.org; exPresident of CEPR

CEPR Policy Research