Oceania 1648 CE
The first European sailors have now appeared in Oceania.
What is happening in Oceania in 1648CE
By this time, long-distance voyaging is mostly a thing of the past for the Polynesians. However, the first European sailors have now appeared in these waters, and some of the major islands, including Australia and New Zealand, have either been sighted or visited.
On Easter Island, the last and greatest phase of statue construction suddenly comes to an end about now, although the inhabitants apparently continue to venerate these great objects. The social structure which produced the statues presumably continues largely intact.
In around 1550 or a little later, sweet potatoes were introduced into the New Guinea highland farming culture. This has led to to much more intensive farming, and so to a large expansion of population.