Research on tiny soil layers extracted from the Tam PÃ Ling cave in northeastern Laos has enhanced the understanding of some of the earliest signs of Homo sapiens in mainland Southeast Asia, according to a group of archaeologists from Flinders University and their international collaborators.
For the last 14 years, a team comprising scientists from Laos, France, the United States, and Australia has been investigating this site, which has yielded some of the oldest fossil records of our direct ancestors in the region.
A recent study led by PhD candidate Vito Hernandez and Associate Professor Mike Morley from the College of Humanities, Arts and Social Sciences has successfully recreated the ground conditions in the cave spanning from 52,000 to 10,000 years ago.
“By employing a method called microstratigraphy at the Flinders Microarchaeology Laboratory, we could interpret the historical conditions of the cave and find evidence of human activities around Tam PÃ Ling,” states Hernandez.
“This process also allowed us to uncover the exact ways in which some of the earliest modern human fossils found in Southeast Asia were deposited deep inside the cave.”
Microstratigraphy enables researchers to examine soil closely, revealing structures and elements that retain information about past environments as well as indications of human and animal activities that could have been missed during excavation due to their small scale.
The human remains found at Tam PÃ Ling date back between 86,000 and 30,000 years. However, prior to this study, there had been no thorough examination of the sediments surrounding these fossils to understand the manner of their deposition or the environmental conditions at that time.
In a publication in Quaternary Science Reviews, the study’s results demonstrate that the cave’s conditions varied significantly, shifting from a moderate climate with frequent wetness to periods of seasonal dryness.
“These environmental changes affected the cave’s internal structure and likely influenced how sediments, such as human fossils, settled within its confines,” says Associate Professor Morley.
“The debate over how early Homo sapiens came to be entombed deep within the cave has been ongoing, but our sediment analysis suggests that the fossils were likely washed into the cave as loose sediments and debris over time, probably transported by water from the surrounding hills during heavy rains.”
The researchers also discovered fine traces of charcoal and ash in the cave’s sediments, indicating that forest fires may have occurred in the area during drier spells or that humans had utilized fire, either inside the cave or at its entrance.
“This study has opened new avenues of understanding regarding how our ancestors navigated the shifting forest landscapes of Southeast Asia during times of climate variability,” remarks study co-author Assistant Professor Fabrice Demeter, a palaeoanthropologist from the University of Copenhagen who has been directing the international research efforts at Tam PÃ Ling since 2009.
