Map of Southeast Asia showing the location of Calio in southern Sulawesi.
Archaeologists led by Budianto Hakim of Indonesia’s National Research and Innovation Agency (BRIN) and Professor Adam Brumm from Griffith University’s Australian Research Centre for Human Evolution have uncovered evidence of tool-making on the Indonesian island of Sulawesi dating back 1.04 million years. The identity of the toolmakers remains unknown, as no hominin fossils have yet been found on the island. Their discovery has just been published open-access in Nature.
The most likely candidates are Homo erectus or a descendant population that adapted to Sulawesi’s distinctive environment. The island lies close to Flores, home of the diminutive ‘Hobbit’ (H. floresiensis), thought to have evolved from H. erectus through island dwarfism, a process that also produced the miniature elephants of Flores. A related discovery was made in 2019 on Luzon in the Philippines, where H. luzonensis—another likely offshoot of H. erectus—was identified. It is therefore entirely plausible that H. erectus, or one of its evolutionary branches, was present and making tools on Sulawesi more than a million years ago.
For creationists, such finds are troublesome because they align seamlessly with evolutionary theory, showing hominins branching, adapting, and diversifying in different environments, just as Darwin and Wallace first described in 1859. They also highlight the profound role of environment in shaping evolutionary outcomes.
For science, the discovery is particularly significant because it implies that an early hominin was capable of undertaking sea crossings across the formidable ‘Wallace Line’—a biogeographic boundary that long isolated the fauna of Australasia from mainland Asia by preventing the natural dispersal of terrestrial animals.
How the Age Was Determined. To date the tools from Sulawesi, researchers combined two complementary methods: uranium-series dating and electron spin resonance (ESR) dating.The team’s findings are further explained in a Griffith University news and analysis article.
By applying both techniques, the Sulawesi team arrived at a robust age of 1.04 million years, with each method reinforcing the other. This dual approach greatly increases confidence in the result and effectively rules out the possibility of a much younger age.
- Uranium-series dating measures the radioactive decay of uranium into thorium in calcium carbonate deposits, such as those that form around fossils or artefacts. Importantly, only uranium (which is soluble) is taken up at the time of deposition, while thorium (which is insoluble) is excluded. This means that any thorium detected later must have formed entirely from the decay of uranium. Unlike some other radiometric techniques, there is no need to know the initial isotope ratios — a common but misplaced criticism often raised by creationists against radiometric dating in general.
- Electron spin resonance (ESR) dating works by detecting trapped electrons in minerals like quartz or tooth enamel. These electrons accumulate over time as a result of natural background radiation. Measuring the trapped electron population provides an estimate of how long the material has been exposed since it was last “reset” (for example, by heat or sunlight).
Oldest evidence of humans on ‘Hobbit’s’ island neighbour discovered – who they were remains a mystery
Recent findings, made by Griffith University researchers, show that early hominins made a major deep-sea crossing to reach the Indonesian island of Sulawesi much earlier than previously established, based on the discovery of stone tools dating to at least 1.04 million years ago at the Early Pleistocene (or ‘Ice Age’) site of Calio.
Budianto Hakim from the National Research and Innovation Agency of Indonesia (BRIN) and Professor Adam Brumm from the Australian Research Centre for Human Evolution at Griffith University led the research published in Nature.
A field team led by Hakim excavated a total of seven stone artefacts from the sedimentary layers of a sandstone outcrop in a modern corn field at the southern Sulawesi location.
Excavations at Calio in southern Sulawesi, Indonesia.Credit: BRIN
In the Early Pleistocene, this would have been the site of hominin tool-making and other activities such as hunting, in the vicinity of a river channel.
The Calio artefacts consist of small, sharp-edged fragments of stones (flakes) that the early human tool-makers struck from larger pebbles that had most likely been obtained from nearby riverbeds.
The Griffith-led team used palaeomagnetic dating of the sandstone itself and direct-dating of an excavated pig fossil, to confirm an age of at least 1.04 million years for the artefacts.
Previously, Professor Brumm’s team had revealed evidence for hominin occupation in this archipelago, known as Wallacea, from at least 1.02 million years ago, based on the presence of stone tools at Wolo Sege on the island of Flores, and by around 194 thousand years ago at Talepu on Sulawesi.
The island of Luzon in the Philippines, to the north of Wallacea, had also yielded evidence of hominins from around 700,000 years ago.
This discovery adds to our understanding of the movement of extinct humans across the Wallace Line, a transitional zone beyond which unique and often quite peculiar animal species evolved in isolation.
It’s a significant piece of the puzzle, but the Calio site has yet to yield any hominin fossils; so while we now know there were tool-makers on Sulawesi a million years ago, their identity remains a mystery.
Professor Adam Brumm, co-senior author
Australian Research Centre for Human Evolution
Griffith University
Brisbane, Queensland, Australia.
Map of Southeast Asia showing the location of Calio in southern Sulawesi.
Stone tools dated to over 1.04mya, scale bars are 10mm.Credit: M W Moore
The original discovery of Homo floresiensis (the ‘hobbit’) and subsequent 700,000-year-old fossils of a similar small-bodied hominin on Flores, also led by Professor Brumm’s team, suggested that it could have been Homo erectus that breached the formidable marine barrier between mainland Southeast Asia to inhabit this small Wallacean island, and, over hundreds of thousands of years, underwent island dwarfism.
Professor Brumm said his team’s recent find on Sulawesi has led him to wonder what might have happened to Homo erectus on an island more than 12 times the size of Flores?Sulawesi is a wild card – it’s like a mini-continent in itself. If hominins were cut off on this huge and ecologically rich island for a million years, would they have undergone the same evolutionary changes as the Flores hobbits? Or would something totally different have happened?
Professor Adam Brumm.
Publication:
Abstract
The dispersal of archaic hominins beyond mainland Southeast Asia (Sunda)1 represents the earliest evidence for humans crossing ocean barriers to reach isolated landmasses2,3,4. Previously, the oldest indication of hominins in Wallacea, the oceanic island zone east of Sunda, comprised flaked stone artefacts deposited at least 1.02 ± 0.02 million years ago (Ma) at Wolo Sege on Flores5. Early hominins were also established on the oceanic island of Luzon (Philippines), as indicated by both stone artefacts and cut marks on faunal remains dating to between 777 and 631 thousand years ago (ka) at Kalinga6. Moreover, fossils of extinct, small-bodied hominins occur on Flores (Homo floresiensis)7,8,9,10,11,12 and Luzon (Homo luzonensis)13. On Sulawesi, the largest Wallacean island, previous excavations revealed stone artefacts with a minimum age of 194 ka at the open site of Talepu in the Walanae Depression14, long preceding the earliest known presence of modern humans (Homo sapiens) in the region (73–63 ka in Sunda)15. Here we show that stone artefacts also occur at the nearby site of Calio in fossiliferous layers dated to at least 1.04 Ma and possibly up to 1.48 Ma, using palaeomagnetic dating of sedimentary rocks and coupled Uranium-series (U-series) and electron-spin resonance (US–ESR) dating of fossil teeth. The discovery of Early Pleistocene artefacts at Calio suggests that Sulawesi was populated by hominins at around the same time as Flores, if not earlier.Fig. 1: Map of the study area.a, The location of Sulawesi within the Wallacean archipelago (Wallacea)—the zone of oceanic islands between the Asian and Australian continental regions (Sunda and Sahul, respectively). MSL, mean sea level. b, The southwestern peninsula of Sulawesi, showing the locations of the Talepu (1) and Calio (2) sites on opposite sides of the Walanae River. Sources of map data: General bathymetric maps (https://www.gebco.net/data_and_products/gridded_bathymetry_data/); DEMNAS Badan Informasi Geospasial (https://tanahair.indonesia.go.id/demnas/#/demnas).
Fig. 2: Stone artefacts recovered from Early Pleistocene deposits at Calio.a, Artefact 1: a large chert flake discovered partially exposed on the surface in a heavily cemented conglomerate. A black linear mineral stain marks the boundary between the exposed part of the flake and the portion embedded in the sandstone. b, Artefact 2: a medium-sized retouched flake struck from a core made from brecciated chert. The arrows indicate the direction of retouch scars across the dorsal face. c, Artefact 3: a small flake struck from a water-rolled chert cobble. d, Artefact 4: a small flake with moderate taphonomic (that is, non-cultural) flaking to both faces (it is broken diagonally). e, Artefact 5: the proximal end of a large flake broken by weathering. f, Artefact 6: a medium-sized redirecting flake struck onto a relatively flat cortical surface of a water-worn chert cobble. g, Artefact 7: a heavily abraded flake with moderate to heavy taphonomic flaking to both faces. Scale bars, 10 mm.
Hakim, B., Wibowo, U.P., van den Bergh, G.D. et al.
Hominins on Sulawesi during the Early Pleistocene.
Nature (2025). https://doi.org/10.1038/s41586-025-09348-6
Copyright: © [year] The authors.
Published by [publisher]. Open access.
Reprinted under a Creative Commons Attribution 4.0 International license (CC BY 4.0)
Discoveries like this underline that human evolution was never a straight march of progress but a complex, branching process, with populations adapting in different ways to the challenges of their environments. Sulawesi now joins Flores and Luzon in showing how early hominins spread and diversified across island Southeast Asia long before the emergence of modern humans.
The age of the Sulawesi tools is significant not just for what it reveals, but for what it implies: these early hominins had both the resourcefulness and determination to cross dangerous sea barriers and establish themselves in new lands. Such achievements speak of a species capable of innovation and adaptability — traits that ultimately carried our lineage to every corner of the globe.
For science, the evidence fits seamlessly into an evolutionary framework, adding another independent line of confirmation for Darwin and Wallace’s theory. For creationists, however, it presents yet another awkward anomaly: a million-year-old chapter of human history that their dogma cannot accommodate. The facts remain the same — and they tell one story only: the story of evolution.
Advertisement
What Makes You So Special? From The Big Bang To You
How did you come to be here, now? This books takes you from the Big Bang to the evolution of modern humans and the history of human cultures, showing that science is an adventure of discovery and a source of limitless wonder, giving us richer and more rewarding appreciation of the phenomenal privilege of merely being alive and able to begin to understand it all.
Ten Reasons To Lose Faith: And Why You Are Better Off Without It
This book explains why faith is a fallacy and serves no useful purpose other than providing an excuse for pretending to know things that are unknown. It also explains how losing faith liberates former sufferers from fear, delusion and the control of others, freeing them to see the world in a different light, to recognise the injustices that religions cause and to accept people for who they are, not which group they happened to be born in. A society based on atheist, Humanist principles would be a less divided, more inclusive, more peaceful society and one more appreciative of the one opportunity that life gives us to enjoy and wonder at the world we live in.
Amazon
Amazon
Amazon
Amazon
Amazon
Amazon
Amazon
Amazon
All titles available in paperback, hardcover, ebook for Kindle and audio format.
Prices correct at time of publication. for current prices.
No comments :
Post a Comment
Obscene, threatening or obnoxious messages, preaching, abuse and spam will be removed, as will anything by known Internet trolls and stalkers, by known sock-puppet accounts and anything not connected with the post,
A claim made without evidence can be dismissed without evidence. Remember: your opinion is not an established fact unless corroborated.