Humans arrived in Australia 18,000 years earlier than previously thought

A new research focusing on excavations carried out in 2015 at the Madjedbebe site in Kakadu in northern Australia suggests that early humans arrived in Australia at least 65,000 years ago - or about 18,000 years earlier than what archaeologists previously thought.

Origin of Aboriginal culture in Australia

Scientists have believed that Prehistoric humans appeared in Africa about 200,000 years ago, and first left the continent sometime between 100,000 years and 60,000 years ago. Scientists also believe that humans first arrived in Australia (from Africa) sometime between 47,000 years to 60,000 years ago.

The new findings, however, push back the origin of Aboriginal culture in Australia. They also have major implications for the scientific understanding of why megafauna in Australia went extinct, and, whether these early humans ever had any interaction with Homo floresiensis—a “hobbit-like” species that lived on the Flores Island in Indonesia.

Artifacts found at Madjedbebe

Madjedbebe, located about 300 km east of Darwin, is a rock shelter in Australia's Northern Territory. This site, first discovered in the 1970s, is a heaven for archeologists as thousands of ochres, bones, stone tools and plant remains have been unearthed from this site in the past 44 years. During 2015 excavation, archeologists discovered grinding stones, ax heads, and a variety of other artifacts from a cave in this area.

A research team, including students and faculty from the University of Queensland and the University Of Washington, evaluated these artifacts using different techniques. The age of these ancient tools was determined using radiocarbon dating and optical stimulated luminescence techniques.

The sediment samples from Madjedbebe were tested at Geoarchaeology lab on the Seattle campus of the University of Washington.

The properties of hundreds of dirt samples were also examined to determine the time when ancient Australian humans lived in the region. Researchers also used a scanning electron microscope to analyze the size of the grains of dirt and the plant matter in the samples. The results of all these tests suggested that early humans arrived in Australia at least 65,000 years ago.

Analysis of carbon isotopes found in sediment revealed that the vegetation in Madjedbebe remained stable during the time of human occupation, and there was no major environmental change at that time. The findings also supported the theory that Homo sapiens evolved in Africa and later dispersed to other parts of the world.

Support of Mirarr people during this research

During this study, extensive cooperation between the research team and the local Aboriginal community was achieved. The Gundjeihmi Aboriginal Corporation that represented the local Mirarr people supervised the excavation work and also reviewed the findings. According to the team, the Mirarr people were very much interested in knowing more about the early human settlements in Australia.

Detailed findings of the study have been published in the journal Nature.