Recycle alert: I originally posted this on my website in October 1998. I recycled part of it several years later with some changes to the point of divergence.
What actually happened: Farming came to the island of New Guinea early--arguably as early as anywhere else in the world. In the highlands of New Guinea there is evidence of farming going back close to ten thousand years. In some other areas of the world, like the Middle East and China, the start of farming was followed in a fairly short time by a rapid expansion of populations, then by the advent of states and empires. New Guinea agriculture didn't follow that path. It remained restricted to the highlands for thousands of years. Populations grew, but comparatively slowly. New Guinea farmers didn't swamp the hunter-gatherer populations around them. New Guinea changed over the next ten thousand years, but slowly. It was still in the stone age when Europeans arrived. The areas around New Guinea, and even parts of the coast of New Guinea, were populated for the most part by Austronesian people (The group which includes the Polynesians and several related people.) The Austronesians apparently came from southern China or the area around Taiwan. They started their agricultural revolution long after New Guinea, but they expanded rapidly once agriculture caught on.
What might have happened: New Guinea started early enough to have become one of the cradles of civilization alongside China and the Middle East. This scenario will look at three questions: First, why didn't they? Second, what factors could have changed to let them play that role? Third, what would result from them playing that role?
Why didn't New Guinea become a cradle of civilization? There were probably a lot of contributing factors.
- Isolation from other emerging centers of agriculture.
- Difficult travel within the island itself.
- Crops which didn't adapt well to life outside the New Guinea highlands
- Lack of large animals to domesticate
- Crops which offered relatively small advantages over hunter-gathering
Which of those factors could have changed? New Guinea had some relatively large animals up until somewhere in the last 40,000 to 50,000 years. They were marsupials called diprotodonts, distant relatives of kangaroos and wombats. The New Guinea species were relatively small for diprotodonts--no more than 600-700 pounds for the largest species.
Diprotodonts died out both in Australia and New Guinea. Judging from their fossils, they were slow moving and probably very easy for human hunters to kill. There is some controversy over whether humans or climate killed them off.
In the case of the diprotodonts in New Guinea I tend to think humans were probably to blame. If they were, that gives us a Point of Divergence. Let's say that for some reason the highland tribes develop a taboo against killing one of the smaller diprotodonts--something in the 200-300 pound range. There have been cases where that sort of thing allowed animal species to survive. A recently discovered New Guinea tree kangaroo apparently survived in a limited area because local tribes didn't hunt it. Diprotodonts were somewhat larger animals, and the taboo would have to cover a large enough area to maintain a viable population, but that isn't impossible. The taboo wouldn't have to last forever. It would just have to last long enough for the locals to discover the benefits of domesticating rather than killing the animals.