Evolutionary theory and the historical development of dry-land agriculture in north Kohala, Hawai'i

This GIS analysis of the dry-land agricultural field system in Kohala on the island of Hawai'i reveals patterning that is explained by evolutionary ecological principles set within a selectionist framework. The ca. 55 km(2) fixed-field system was developed through establishment, expansion, and intensification from the sixteenth until the early nineteenth century. During this time, differential growth rates and levels of intensification occurred in diverse locales. The development of the field system was characterized by changes in the size of the fields, variability in field size, the size of production communities the level of distribution of production, and the spatial distribution of fields. The most important factors influencing the differential temporal and spatial changes included differences in the abundance of marine resources, variability in the distance between the coast and the inland fields, differences in the amount of variation of rainfall levels over a given distance, and the insurance or subsidy that chiefs could offer to residents to initiate farming in the least optimal locations. Selective pressures within the heterogeneous environment of north Kohala provided the context in which subsistence strategies shifted from a focus on optimizing energy returns to one of stabilizing returns via risk aversion.