Tracking the dispersal of humans from the African Rift to the Pacific Rim using biomolecular approaches

Modern humans (Homo sapiens) evolved in Africa, dispersed into Eurasia, and reached the vast landmass of Sahul (present-day Australia, Papua New Guinea, and Tasmania) by ~60,000 years ago. During this remarkable expansion, interbreeding between H. sapiens and other hominin taxa shaped and redefined our species’ genetic profile. Yet, the scarcity of fossils and ancient molecular data from Africa and Sahul, the starting and ending points of this journey, leave unanswered questions regarding the origins, age, and genetic imprints of the groups venturing from the African homeland, and of those reaching Sahul. RIFT-to-RIM is an ambitious project that builds on the foundation of the PI’s previous ERC work (FINDER) in Asia, and aims to rectify the dearth of fossils and genetic evidence from two under-researched regions of the world, sub-Saharan Africa and Sahul. Through a novel and systematic combination of cutting-edge biomolecular methodologies, a carefully designed workflow targets 21 African and Papuan sites dating to between 200,000-10,000 years ago. To minimise the impact of collagen and DNA degradation the project relies heavily on high-elevation sites, coupled with analytical developments for poorly preserved samples. Thousands morphologically non-diagnostic bones (~180,000) will be assessed non-destructively using Near-infrared spectroscopy, and a fraction of them (~20,000) will be determined taxonomically using palaeoproteomics, primarily ZooMS. Newly identified hominin bones will undergo ancient DNA, dating and isotopic analyses. Sediments from new and previously-excavated sites will be screened for modern human DNA evidence.The RIFT-to-RIM workflow maximizes our chances of identifying, dating, and genetically characterizing early H. sapiens in regions where such data are exceptionally rare. Ultimately the project will generate a wealth of new evidence from key regions of the world and will help decod the intricate mosaic that defines modern humans today.