A few years ago on the Pacific Island of Tonga, I stood a few yards distant from a little shed as Feinga explained to me what he did with the many yams from his garden (Fig. 1). Yams, a highly desired food in much of Oceania, are often at the center of village events today as they were in the past. In 1777, explorer Captain James Cook witnessed the 'inasi ceremony, or annual tribute presentations, where yams and other food were presented to the chiefs of Tonga. There, as in other parts across Polynesia, tributes to ruling elites and trading between islands involved managing large quantities of food, requiring numerical operations such as addition, multiplication, and division of these resources both within and between islands. As an important management tool, the system to count these quantities arose and was maintained through cumulative social learning and innovation, a prime example of Darwinian evolution. Over the last decade, our evolutionary understanding of cultural complexity and dynamics has significantly increased as empirical studies (1-3) address the mathematical theory laid out in the 1980s (4, 5). Among key questions are how new cultural variation is introduced, and what advantages enable a cultural variant to become common in society. In PNAS Bender and Beller (6) address these two questions, detailing the innovative manner in which a small Pacific Island population represented quantities, or how they counted, before European contact.
展开▼
