Important findings regarding the settlement of modern humans in the region during an ancient period of climate change were uncovered during excavation work in a cave in Laos. The excavations revealed traces of human and animal activities, in addition to the ground conditions dating back 50,000 to 30,000 years ago.

An archaeological site unearthed during excavations in Laos presents significant evidence of the oldest human settlements in Southeast Asia. The study sheds light on how the first humans settled in the region during an ancient period of climate change.

Published in the journal Quaternary Science Reviews, the study reconstructed ground conditions from 52,000 to 10,000 years ago at the Tam Pà Ling cave in Laos.

90,000-YEAR-OLD FOSSILS HAD BEEN FOUND

Previous excavations had unveiled human fossils dating back 30,000 to 90,000 years in the cave, indicating that modern humans spread to the region earlier than previously thought. However, the detailed analysis of the surrounding sediments had not been done in previous excavations.

Researchers from Flinders University in Australia attempted to understand past environmental changes by microscopically analyzing soil samples taken from the cave. The findings helped determine the conditions under which the oldest modern human fossils in Southeast Asia settled in the depths of the cave. The analyses also revealed traces of human and animal activities that had been overlooked in previous excavations, providing more insights into adapting to environmental changes in tropical conditions.

Research showed that the cave had remained wet for a long time between 50,000 and 30,000 years ago, transitioning from a temperate to humid climate. The researchers suggested that human fossils might have been carried into the depths of the cave over time by accumulating loose sediments during heavy rainfall. Signs also indicated that the cave experienced a period of drought around 24,000 years ago before quickly returning to wet and temperate conditions.

The study highlighted the fluctuating conditions in the cave from having frequently wet ground in a temperate climate to seasonally becoming dry. The region likely experienced forest fires during drier periods. The researchers also mentioned that humans visiting the cave might have lit fires inside or near the entrance as an alternative. Fabrice Demeter, one of the study’s authors, stated: “This research has provided unique insights into the dynamics of our ancestors, dispersed in Southeast Asia among its constantly changing forest covers and variable regional climate instabilities.”