The expansion of human civilization in the Pacific

I don’t know about you, but I’ve always been fascinated by the expansion of human settlement in the Pacific Ocean. So vast an expanse of water (covering about 28% of the surface of the globe, greater than the combined area of all the land masses on the planet); so few land masses scattered across it, most of them so tiny as to be invisible on a typical map; such enormous distances between them. How did humanity spread across the Pacific?

Courtesy of the ever-informative Al Fin, I see that the equally interesting Dienekes has come up with the latest information.

For many years people pondered whether human settlement of the Pacific started from South America. Thor Heyerdahl tried to prove this hypothesis in his famous Kon-Tiki Expedition, which occupied me for many hours of reading pleasure in my youth.

Nevertheless, this theory appears to have been discredited by investigations of DNA and Bayesian phylogenetics, according to Dienekes, who cites recent studies in the field. The language is academic and technical, but repays investigation.

Hypotheses on the origin of the Austronesian settlers of the Pacific are divided between a recent “pulse-pause” expansion from Taiwan and an older “slow-boat” diffusion from Wallacea. We used lexical data and Bayesian phylogenetic methods to construct a phylogeny of 400 languages. In agreement with the pulse-pause scenario, the language trees place the Austronesian origin in Taiwan approximately 5230 years ago and reveal a series of settlement pauses and expansion pulses linked to technological and social innovations. These results are robust to assumptions about the rooting and calibration of the trees and demonstrate the combined power of linguistic scholarship, database technologies, and computational phylogenetic methods for resolving questions about human prehistory.

This chart shows how the study projects trans-Pacific expansion to have occurred.

Try to put yourself in the position of those early explorers who set out across such vast, trackless wastes of water. What drove them? Why leave land, and set out towards who knew what? The first pioneers could have had no inkling that land existed out there – and many of them must have died on their voyages of discovery, because land masses in the Pacific are few and far between. How many died? How did they feel, lying baking beneath the harsh sun, knowing that their water and food had run out? To which Gods did they call in their despair?

And what of those who found land, and a new home? They would most likely never go back. Did they cling to the traditions of their homelands? How long did it take for newer rituals and customs to overcome the heritage they brought with them? How did the various Polynesian and other micro-cultures of the Pacific develop? How long did it take? What were their origins?

All fascinating questions, many probably never to be answered due to the immense gap between the origins of these people and the present day . . . but interesting nonetheless.

Peter