East Polynesian Islands as Models of Cultural Divergence: The Case of Rapa Nui and Rapa Iti

The diverse island societies of East Polynesia are well-suited as models for comparative evolutionary analysis. Settled ca. 750 BP by a common ancestral population, colonists of the remote corners of the Pacific shared a pool of cultural traits that included commensal species, language, technology, and other cultural practices. Following colonization however, island populations diverged in language, subsistence practices, degree of territoriality, settlement patterns, investment and forms of monumental architecture, and social organization. Driven by historical circumstances and varied environmental conditions, this divergence presents evolutionary case studies of alternative paths of cultural change. One explanatory approach to this evolutionary divergence involves isolating the critical ecological parameters that likely constrained and shaped the diverse history of island populations. Here, we offer a comparative evolutionary analysis that explores the divergent histories of two marginal East Polynesian islands: Rapa Nui and Rapa Iti.