Shellfishing and the Colonization of Sahul: A Multivariate Model Evaluating the Dynamic Effects of Prey Utility, Transport Considerations and Life-History on Foraging Patterns and Midden Composition

Archaeological evidence of shellfish exploitation along the coast of Sahul (Pleistocene Australia-New Guinea) points to an apparent paradox. While the continental record as a whole suggests that human populations were very low from initial colonization through early Holocene, coastal and peri-coastal sites dating to that time are dominated by small, low-ranked, littoral taxa to the near-complete exclusion of large, higher ranked, sub-littoral species, precisely the opposite of theory-based expectations, if human populations and predation rates were indeed as low as other data suggest. We present a model of shellfish exploitation combining information on species utility, transport considerations, and prey life-history that might account for this apparent mismatch, and then assess it with ethnographic and archaeological data. Findings suggest either that high-ranked taxa were uncommon along the Pleistocene coastlines of Sahul, or that abundant and commonly taken high-ranked prey are under-represented in middens relative to their role in human diets largely as a function of human processing and transport practices. If the latter reading is correct, archaeological evidence of early shellfishing may be mainly the product of subsistence activities by children and their mothers.