Photographer David Doubilet first dove below the surface at age 8 and has spent a lifetime making underwater images. He talks to NPR about his new book: <a href="https://www.phaidon.com/store/photography/two-worlds-above-and-below-the-sea-9781838663186/"><em>Two Worlds: Above and Below the Sea</em></a><em>. </em>
Widely held assumptions about static societies during the early-middle Holocene (c. 10,000–3300 BP) in the Willaumez Peninsula, Papua New Guinea are challenged by a hypothetical reconstruction of social negotiations that we propose were embedded within the manufacture of large obsidian stemmed tools that circulated as cultural valuables. Made by skilled knappers, these artefacts were manufactured in stages (quarrying, preform production, shaping, hafting, and re-hafting) often segregated in discrete and possibly restricted locations. The successful completion of a large obsidian stemmed tool may have required effective management to negotiate multiple social networks, thereby enhancing the status of those who directed the process. Social connections forged and re-inforced to support the production process may also have been enhanced by ritual practices. Through the social links created and strengthened by the process of its crafting and the subsequent ceremonies and exchanges in whic