Anthony (1990) has urged that prehistoric migrations be considered as structural processes, the study of which can be approached through general principles derived from recent studies of migration in demography and geography. It may be worth examining some of these postulated principles in the light of the Lapita evidence.^[3] Anthony notes that a common feature of long-distance migration is leapfrogging, great distances being crossed and large areas bypassed, “through the agency of advance ‘scouts’ who collect information on social conditions and resource potentials and relay it back to the potential migrants” (1990:902). He suggests that archaeologically this should be recognizable by an earlier smallscale penetration prior to the large-scale migration, and notes significantly that the archaeological signature of leapfrogging, “should resemble ‘islands’ of settlement in desirable or attractive locations, separated by significant expanses of unsettled, less desirable territory” (1990:903).

This of course is precisely the Lapita settlement pattern. “Scouts” too may explain anomalous Lapita assemblages such as the somewhat ephemeral rockshelter occupation on Nissan, at the northern end of the Solomons, of the Halika phase, contemporary with the earliest Lapita further to the north and west and stratigraphically below a classic Lapita assemblage at one of the excavated sites (Spriggs 1991a). Lapita rockshelter occupations on Lakeba in Eastern Fiji, interpreted by Best (1984) as representing a “strandlooper” phase of Lapita before the establishment of a fully agricultural economy, would also fit the pattern.

Another feature of long-distance migration discussed by Anthony is its resemblance to a stream, the migrants proceeding along well-defined routes towards specific destinations, and often originating from a highly restricted point of origin. The archaeological signature would be distribution of regionally defined artefact types from a circumscribed home region to a specified destination. The pattern of obsidian distribution in the western Pacific could certainly be interpreted in this framework (cf. Green’s (1987:246) discussion of maintaining “ties” with the homeland by continuing to import obsidian from Bismarcks sources when a local alternative was available). Anthony further notes that migration streams often continue to flow in a given direction despite circumstances quite changed from those that prompted the initial movement:

Kinship linkages, dependence, and the reduction of obstacles may attract a secondary flow that is quite different in goal orientation and composition from the initial migrant group. Such a chronological shift in group composition and organization might well have archaeological effects (1990:904).

The changes which occur at the end of Lapita may form an example of such a secondary stream. Migration streams, Anthony notes, favour the creation of “apex-families” which might establish more permanent status differentiation as communities mature. The suggested hierarchical nature of Lapita society (see Kirch 1988b for discussion) could well have been related to such processes.

A third feature of migration is return migration, a counterstream returning back to the migrants’ place of origin, particularly when opportunities are similar at the origin and destination points. Some examples of long-distance “trade” might represent goods carried by return migrants. In this regard it is worth remembering the Talasea obsidian in Sabah and the similarities in pottery decoration to Lapita of assemblages in various parts of island Southeast Asia which date a few hundred years later than the earliest Lapita in Island Melanesia (see above).

A fourth feature is migration frequency, migrants tending to belong to groups who have a tradition of migration. Within particularly the younger age groups of a population, migration increases the probability that further migration will occur. Anthony (1990:905) suggests that this self-propagating tendency can partially explain flurries of migratory activity that characterize some portions of the archaeological record. The rapidity of spread of Lapita from the Bismarcks to Samoa in only a few hundred years would seem to be a classic example of this pattern.

Anthony mentions as a final pattern, that of migration demography, often skewed towards males in the initial stages of more recently documented migrations. Some of the “bottlenecks” detected by mitochondrial DNA studies, for instance in the settlement of Eastern Polynesia, might usefully be examined with this in mind. Further modelling of Lapita-period population dynamics along the lines started by McArthur, Saunders and Tweedie (1976) and Black (1978) are clearly needed.