Recent excavations on the Indonesian island of Sulawesi have revealed seven stone tools, indicating that ancient human relatives, possibly a Homo species, may have arrived on the island between 1 million and 1.5 million years ago, significantly earlier than previously thought.

The excavation, led by Budianto Hakim from the National Research and Innovation Agency of Indonesia, uncovered these tools at a site known as Calio, embedded in sedimentary layers.

The geological context of the site suggests an age of nearly 1.5 million years for the tools, which were made from local chert and shaped using a percussion flaking technique.

These artifacts, which display signs of advanced tool-making skills, were likely used for cutting and scraping, indicating the toolmakers had developed specific skills.

This discovery adds to the understanding of early human migration across the Wallace Line, which separates distinct animal species evolved in isolation.

The study, titled 'Hominins on Sulawesi during the Early Pleistocene', was published in the journal Nature on August 6, 2025, highlighting the importance of archaeological studies in reshaping the narrative of early human history.

While the means by which these early humans reached Sulawesi is unclear, it is speculated they may have arrived accidentally on natural rafts of floating vegetation.

Experts caution against prematurely concluding migration paths without further evidence, emphasizing the need for continued research on these ancient human relatives.

The findings raise questions about the evolutionary changes that may have occurred in hominins on Sulawesi, a larger and ecologically diverse island compared to Flores.

Homo erectus is suggested as the most likely candidate for making the sea crossings, as they were present in Southeast Asia at that time and made similar tools.

Professor Adam Brumm, leading the research team, notes that this discovery enhances understanding of early human migration and adaptation in Southeast Asia.

Future archaeological efforts will focus on finding direct remains of the toolmakers on Sulawesi and understanding the dynamics of early human inhabitation in the region.