A PROLONGED drought thousands of years ago may have played a decisive role in the disappearance of
Homo floresiensis, according to new research by an international team that includes scientists from the University of Wollongong (UOW).
The study, published in
Communications Earth & Environment, suggests the small-bodied human species left Liang Bua on the Indonesian island of Flores after occupying it for about 140,000 years as conditions became increasingly dry.
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By analysing chemical signals preserved in cave stalagmites and isotopic data from fossilised teeth of the pygmy elephant
Stegodon florensis insularis, researchers reconstructed environmental changes over time.
Their findings indicate a drying trend beginning around 76,000 years ago that intensified into a severe drought between 61,000 and 55,000 years ago, closely matching the period when
Homo floresiensis disappeared.
Lead author UOW Honorary Professor Dr Mike Gagan said the ecosystem around Liang Bua became dramatically drier around the time the species vanished, with summer rainfall declining and riverbeds becoming seasonally dry.
Researchers said the pygmy elephant population declined sharply around 61,000 years ago, removing a key food source and increasing pressure on
Homo floresiensis as surface freshwater also diminished.
They said extended drought and mounting competition for limited food and water may have forced the species to abandon Liang Bua, with the possibility that movements in search of resources brought them into contact with modern humans who were present in the region.
