Peter Bellwood (this volume) has already discussed possible reasons for the expansion of An speakers into the Pacific, although as Anthony (1990:898) points out, the causes of migrations are often extremely complex and in many prehistoric cases proximate causes can no longer be clearly identified. The migrants’ initial success in establishing settlements in the Bismarcks and Solomons may well have been due to the demographic muscle imparted by a full-on agricultural economy moving into a basically hunter-gatherer area. The existence of an already in-place agricultural economy on the mainland of New Guinea may well explain why An settlement there appears to have been delayed for over a thousand years after the Bismarcks were settled (Bellwood 1984). It would be wrong, however, to see the new colonists immediately blanketing the Bismarcks and Solomons. Initial numbers would have been low, settlements were marginal to the larger islands and even before the push through to Polynesia some limited recruitment from local NAn-speaking populations must have taken place to explain certain genetic markers found in Polynesian populations.

The diffusion of agriculture across the An-NAn linguistic boundary must have occurred at some time, as all Bismarcks and Solomons populations are agricultural today whatever language they speak. Over time there must also have been a tendency for whole groups to switch from NAn to An languages in areas such as Manus and New Ireland. On Bougainville the majority of the population never adopted An languages, which mimic the mainland New Guinea pattern in occurring peripherally around the coast (Spriggs 1992). The archaeological study of the An and agricultural “frontier” in the region has barely begun but will produce a much more complex prehistory than we can outline with our present state of knowledge.

Although this and other papers in this volume have inevitably given an Austronesian-centred view of the region, all present Austronesian groups, whether in Melanesia or Polynesia, also share a heritage derived from a Non-Austronesian Melanesian origin, whether it be in the food crops they cultivate, aspects of their material culture and art, certain genetic markers, or in aspects of the structure and lexicon of their languages. This should not be forgotten because (with apologies to Rupert Brooke) there is a corner of an Austronesian field that is forever Non-Austronesian.