The Prehistoric Exploration and Colonisation of the Pacific.

Bahn, Paul G.

GEOFFREY IRWIN. The prehistoric exploration and colonisation of the Pacific. vii+240 pages, 83 figures, 22 tables, 1992. Cambridge: Cambridge University Press; ISBN 0-521-40371-5 hardback |pounds~30 & $49.95.

For some reason, books on Pacific archaeology often seem to have titles that are slightly misleading (or, in the case of Thor Heyerdahl's (1989) Easter Island: the mystery solved, extremely misleading). Like John Terrell's Prehistory in the Pacific Islands of 1986, Geoffrey Irwin's volume might well be assumed to contain a general survey of the ancient cultures of the Pacific Islands, of the kind produced so well in the past by Peter Bellwood. But neither book contains such a synthesis. The paradox of Irwin's title is that it may mislead slightly because it corresponds precisely to the book's content! What he has produced is a very thorough and well-argued account of the development of navigational skills and their application to the exploration and the colonization of the farthest reaches of the Pacific.

Irwin's thesis will be familiar to ANTIQUITY readers since he presented a condensed version in the journal three years ago (Irwin et al. 1990). Leaving behind the traditional and now somewhat stale debates of a few decades ago between those who saw most Pacific exploration as accidental, and those who saw it as driven and purposeful, he has developed the eminently sensible view that, on the whole, one must assume the early navigators were highly competent and wished to avoid risk. Instead of being guided by the fastest rate of advance across the ocean, they chose the methods that ensured the highest chance of survival. Hence, the exploration of the remote Pacific was rapid, purposeful and systematic, but also extremely cautious; and navigational skills became more refined as the colonization proceeded.

In short, he presents us for the first time with a theory of Pacific discovery and colonization which, unlike others of its kind, is truly independent of the patterns of language, culture and biology found in the region at the time of European contact. In the past these data have been used to construct doubtful retrospective models of the earliest settlement; but Irwin takes the alternative route of testing his theory against the data, and meets with considerable success. It is likely that his success will increase in the future, since the archaeological data from the Pacific Islands are improving constantly, and dates are being pushed back in many areas.

Irwin's method is to look carefully at what was feasible in navigation, emphasizing the practicalities of deep-sea sailing, the details of the weather and currents, and the relative accessibility and remoteness of the island targets. He then checks this picture against the archaeological evidence, against what is known of the order in which different islands were settled, and when. One problem here is that it is difficult to differentiate archaeologically between first discoverers and first colonizers, since they were not necessarily one and the same, but that is a minor hiccup.

Finally, the model is further tested by a massive programme of computer simulation, involving tens of thousands of canoe voyages. His simulations avoid many of the pitfalls inherent in such exercises, since they incorporate very specific data on distances between islands and the behaviours and capabilities of boats. They certainly help one to choose among available options, since some results conform to the archaeological evidence, while others are flatly contradicted by it. Irwin's simulations are a worthy successor to the pioneering study of this kind, published 20 years ago by Levison, Ward & Webb, which was the first to prove that Pacific Island settlement must have been intentional. Irwin's work builds on theirs and shows how it was probably done, and in which order.

This is not, then, a general work on Pacific prehistory; its use of archaeological data is sparing and focused, and it pays little attention to questions of the motivation behind the voyages. It is conservative in places (e.g. the date of New Zealand's colonization, which may well be pushed back considerably in the near future) but bold in others, speculating that time Polynesian navigators -- perhaps even people from Easter Island -- may have sailed to South America and returned safely, certainly a more, likely scenario than what he refers to, aptly, as 'Heyerdahl's American diversion'. Irwin was the perfect person to write such a book, bringing together his knowledge of Pacific prehistory and navigation and his practical experience of sailing these waters. The only frustration is that so little of the technical and navigational jargon is explained in words of one syllable for ignorant landlubbers such as myself.

References

HEYERDAHL, T. 1989. Easter Island, the mystery solved. London: Souvenir Press.

IRWIN, G., S. BICKLER & P. QUIRKE. 1990. Voyaging by canoe and computer: experiments in the settlement of the Pacific Ocean, Antiquity 64: 34-50.

LEVISON, M., R.G. WARD & J.W. WEBB. 1973. The settlement of Polynesia: a computer simulation. Canberra. ANU Press.

TERRELL, J. 1986. Prehistory in the Pacific Islands. Cambridge: Cambridge University Press.