Archaeologists from Flinders University and a world team have discovered evidence of the earliest Homo sapiens fossils on the Southeast Asian continent by analyzing microscopic layers of soil at Tam Pà Ling (Monkey Cave) in northeastern Laos.
For 14 years, a team of scientists from Laos, France, the United States and Australia has been studying this place, which provided the oldest fossil evidence of the existence of human ancestors. The latest study, published in Reviews of the quaternary sciencesanalyzes soil from the cave to know environmental conditions dating back tens of hundreds of years.
In previous research, the invention of human fossils at the positioning, estimated to be between 68,000 and 86,000 years old, provided the primary empirical evidence of the presence of Homo sapiens within the region. This discovery chronologically places the arrival of contemporary humans in these areas consistent with the oldest evidence of their presence on the Australian continent.
However, the cave’s steep accessibility, which requires specialized climbing equipment, raises questions on the mechanisms by which the fossils were deposited. Paleontologists hypothesized that the fossils could have been brought by floodwaters somewhat than human activity within the cave. The cave’s lack of artifacts, akin to tools or the stays of a fire, reinforces this suspicion, which has turn out to be a scientific consensus within the interpretation of previous discoveries.
In this study, researchers led by Flinders University PhD student and Associate Professor Mike Morley from the College of Humanities, Arts and Social Sciences provide a brand new perspective by reconstructing soil conditions at Tam Pà Ling between 52,000 and 10,000 years ago. Using microstratigraphic techniques, they successfully identified traces of human activity in and across the cave.
Unlike conventional approaches that focus more on large-scale fossils, microstratigraphy provides a more detailed perspective on past environments. By analyzing microscopic materials akin to ash and charcoal, Hernandez and his team discovered more detailed information in regards to the environmental conditions under which the oldest modern human fossils in Southeast Asia were deposited within the cave.
Soil evaluation indicates that environmental conditions within the cave have modified dramatically over time, fluctuating between wet and dry periods. These environmental fluctuations have significant consequences for sedimentation processes within the cave, including the deposition of human fossils.
Associate Professor Morley argues that the fossils were likely carried into the cave by the flow of water from the encompassing hills in periods of heavy rainfall, after which collected within the cave as sediment.
The presence of a big amount of burnt material within the cave is a robust indicator of past pyrogenic activity. Possible scenarios that might explain this phenomenon include early humans lighting fires or fires in the world carrying charcoal into the cave.
Fires on this region could be of particular interest to researchers of the fossils found there, especially because the area is currently too wet to support such fires. This suggests that the region could have been drier up to now, and evidence of fires may provide insight into this era.
Meanwhile, if the burned material is attributed to bonfires, this theory becomes much more intriguing, because it suggests that the cave had special significance for the people whose stays were found there, and was not only a spot for laundry bones after death. This raises the query of why people made the perilous journey to the cave, and encourages further exploration to find tools and other artifacts.
