![]() ![]() It is generally accepted that modern humans dispersed via coastal routes due to ease of movement and plentiful resources. “No one could have expected that the oldest evidence of modern humans would be found to the west of the expected dispersal route, so far inland, and up in the mountains within a dense rainforest environment – that was a surprise!” “I see this research as a triumph of modern scientific techniques applied to a long-standing problem.”ĭespite fitting in with the recent human dispersal evidence from Morocco and northern Australia and providing the missing 20,000 years in Southeast Asian evidence, the research was not without its surprises. We finished off what Dubois had started all that time ago – but we had modern dating techniques and state-of-the-art scanning techniques on our side. “Along with the location of the cave the importance and significance of these teeth had been lost due to an inability to confidently identify and date them. The analyses confirmed that the teeth are anatomically modern human, indicating that they were present on the Sumatran landscape at that time.Ī barrage of dating techniques were applied to the sediment around the fossils, to overlying and underlying rock deposits in the cave and to associated mammal teeth, indicating that the deposit and fossils were laid down between 73-63 thousand years ago. The teeth were reanalysed using state-of-the-art imaging techniques, allowing insight into enamel thicknesses and junctions between the enamel and dentine, critical for distinguishing human from other primate teeth. The Lida Ajer human teeth were identified as modern human 70 years ago by Hooijer, a Dutch palaeontologist studying orangutan fossils, and while the study was convincing, it lacked comparative studies of contemporaneous human fossils. But, the minute I saw a large calcite column in the entrance I knew we had found the cave dug by Dubois over 120 years earlier.” We stumbled across the cave almost by accident. “We only had a sketch of the cave and a rough map from a copy of Dubois’s original field notebook. “The hardest part was trying to find the site again. Kira and her colleagues rediscovered the site with the intention of establishing a firm chronology for the evidence and testing the modern human attribution of the teeth. Nestled in amongst the dense array of orangutan teeth, Dubois also found two human teeth that were thought to be of great antiquity. “I sometimes feel like my life is like an Indiana Jones movie – finding lost caves in tropical jungles using a weathered old map, recovering fossil treasure to bring back to the museums,” she said. His findings were not lost, now housed in the Lieden museum in the Netherlands, but the exact location of the cave had been lost to scientific and even local knowledge.Īrmed with a copy of a 120-year-old map and plan of the cave, Kira searched endlessly to rediscover this lost archive of evidence that was crucial to the human dispersal story. The site, Lida Ajer, was a ‘lost cave’ excavated over 120 years ago by the ‘Java Man’ discoverer and Dutch palaeoanthropologist, Eugen Dubois. This evidence has been greatly anticipated but has been a long time coming.” “We can now say with some confidence that modern humans had reached the island of Sumatra before 65ka (kilo annum) – when evidence suggests they had already made the crossing to Australia. “You know that your research has been accepted when everyone collectively sighs in relief,” said Kira. ![]() Her lead-authored research recently published in Nature provides evidence for a human presence in Southeast Asia between 73,000-63,000 years ago – almost 20,000 years earlier than previously thought. Dr Kira Westaway from the Department of Environmental Sciences recently discovered the missing evidence that connects the human dispersal timeline from Africa round to Australia and supports an early arrival of modern humans into Australia. This is the enviable position that a Macquarie researcher has found herself in and she couldn’t be more excited. So, when a piece of research comes along that fits in with expectations, connects missing evidence and supports current research, it is welcomed and applauded like a long-lost friend. Rarely does science fit together nicely – invariably new evidence bulldozes through long held ideas, tramples over life works and tends to raise more questions than it answers.
0 Comments
Leave a Reply. |