-1- THE IMPORTANCE OF SCALE IN DETERMINING THE HUMAN POPULATION DISTRIBUTIONS IN THE MARSHALL ISLANDS WILL MCCLATCHEY and K. W. BRIDGES McClatchey, W. and K. W. Bridges (Department of Botany, St. John Laboratory 101, University of Hawai‘i at Manoa, Honolulu, Hawai‘i 96822-2279, U.S.A. THE IMPORTANCE OF SCALE IN DETERMINING THE HUMAN POPULATION DISTRIBUTIONS IN THE MARSHALL ISLANDS. Traditional environmental knowledge has been employed by ancient people in the selection of habitation sites in the landscape. In simple terrestrial systems such as Pacific atolls, the apparent patterns of these kinds of decisions may provide insights into the logic that was employed. Based upon ecological analyses at Ailinginae Atoll, Kapingamarangi Atoll and human demographic data from the Republic of Marshall Islands, we have studied two scales of evidence that address the same issue: sustainable human population survival in the Marshall Islands. The scales that were explored are: selection of an islet on which to live at a particular atoll, and distribution of human population levels across a group of islands. We conclude that different factors are impacting the decisions at different scales. Small island effects seem to explain the selection of islets within an atoll while terrestrial land area explains the distribution of the population across the Marshall Islands. Key Words: Scales, human populations, atoll, Ailinginae Atoll, Marshall Islands, small island effect. A fundamental element of the survival of ancient human populations was selection of an appropriate site in which to live. There are many reasons why people would elect to reside in a particular site. Some of these reasons are based upon fundamental survival possibilities (e.g., availability of food, water, and shelter). Others are based upon environmental factors (e.g., long-term storm patterns, currents and winds, biological diversity, and physical accessibility). Cultural concerns are also likely to be important (e.g., family unit size, social obligations, warfare, and gender roles). For some peoples living in somewhat uniform environments with plenty of resources this may have been an easy task, but for those living in environments with serious resource limitations, the decision could be one of life or death of their genetic (and cultural) lineage. Traditional environmental knowledge as studied by ethnobiologists (Cunningham 2001, Merlin et al. 1994, Peters 1996, Prance et al. 1987) has typically focused upon human interactions with specific resources or ecosystems. The logic behind ancient human colonization decisions has not been identified from modern communities however the