Collapse_ How Societies Choose to Fail or Succeed - Jared Diamond [182]
How and when did Tikopia’s remarkable sustainable economy arise? Archaeological excavations by Patrick Kirch and Douglas Yen show that it was not invented all at once but developed over the course of nearly 3,000 years. The island was first settled around 900 B.C. by Lapita people ancestral to the modern Polynesians, as described in Chapter 2. Those first settlers made a heavy impact on the island’s environment. Remains of charcoal at archaeological sites show that they cleared forest by burning it. They feasted on breeding colonies of seabirds, land birds, and fruit bats, and on fish, shellfish, and sea turtles. Within a thousand years, the Tikopian populations of five bird species (Abbott’s Booby, Audubon’s Shearwater, Banded Rail, Common Megapode, and Sooty Tern) were extirpated, to be followed later by the Red-footed Booby. Also in that first millennium, archaeological middens reveal the virtual elimination of fruit bats, a three-fold decrease in fish and bird bones, a 10-fold decrease in shellfish, and a decrease in the maximum size of giant clams and turban shells (presumably because people were preferentially harvesting the largest individuals).
Around 100 B.C., the economy began to change as those initial food sources disappeared or were depleted. Over the course of the next thousand years, charcoal accumulation ceased, and remains of native almonds (Canarium harveyi) appeared, in archaeological sites, indicating that Tikopians were abandoning slash-and-burn agriculture in favor of maintaining orchards with nut trees. To compensate for the drastic declines in birds and seafood, people shifted to intensive husbandry of pigs, which came to account for nearly half of all protein consumed. An abrupt change in economy and artifacts around A.D. 1200 marks the arrival of Polynesians from the east, whose distinctive cultural features had been forming in the area of Fiji, Samoa, and Tonga among descendants of the Lapita migration that had initially also colonized Tikopia. It was those Polynesians who brought with them the technique of fermenting and storing breadfruit in pits.
A momentous decision taken consciously around A.D. 1600, and recorded in oral traditions but also attested archaeologically, was the killing of every pig on the island, to be replaced as protein sources by an increase in consumption of fish, shellfish, and turtles. According to Tikopians’ accounts, their ancestors had made that decision because pigs raided and rooted up gardens, competed with humans for food, were an inefficient means to feed humans (it takes about 10 pounds of vegetables edible to humans to produce just one pound of pork), and had become a luxury food for the chiefs. With that elimination of pigs, and the transformation of Tikopia’s bay into a brackish lake around the same time, Tikopia’s economy achieved essentially the form in which it existed when Europeans first began to take up residence in the 1800s. Thus, until colonial government and Christian mission influence became important in the 20th century, Tikopians had been virtually self-supporting on their micromanaged remote little speck of land for three millennia.
Tikopians today are divided among four clans each headed by a hereditary chief, who holds more power than does a non-hereditary big-man of the New Guinea highlands. Nevertheless, the evolution of Tikopian subsistence is better described by the bottom-up metaphor than by the top-down metaphor. One can walk all the way around the coastline of Tikopia in under half a day, so that every Tikopian is familiar with the entire island. The population is small enough that every Tikopian resident on the island can also know all other residents individually. While every piece of land has a name and is owned by some patrilineal kinship group, each house owns pieces of land in different parts of the island. If a garden is