Hominin Dispersal and Settlement East of Huxley’s Line: The Role of Sea Level Changes, Island Size, and Subsistence Behavior

The thousands of islands east of Huxley’s Line have never formed a single land mass or been connected to Sunda or Sahul. The earliest records of hominins in this area are stone tools recovered from Pleistocene deposits on Flores and Sulawesi. Subsistence by these hominins as well as the later subsistence patterns exhibited by Homo floresiensis suggest that exploitation of marine resources was, at best, rare and opportunistic. Likewise, the fragmentary hominin remains recovered from Late Pleistocene deposits from Callao Cave in the Philippines exploited large game at the expense of marine resources. In contrast, the earliest zooarchaeological records of modern humans are dominated by marine fish and shellfish and include the earliest evidence of pelagic fishing using shell tools, implying complex fish-capture technology. Pleistocene lithic assemblages on these islands are unspecialized, indicating reduction of predominantly locally available stone to produce flakes and irregularly retouched pieces. By the terminal Pleistocene, records of human subsistence on very small islands indicate almost total reliance on marine foods for protein. We propose that strong links exist between subsistence strategies and dispersal throughout Wallacea, with subsistence strategies available to pre-sapiens hominins in the region being a major limiting factor in their dispersal.