Middle Palaeolithic tools found at Attirampakkam.
Explainers

Explained: How South Indian Stone Tools Challenge Out-of-Africa

The story of human evolution has been a convoluted tale for archaeologists to piece together – and it just got even more tangled.

The currently dominant ‘out-of-Africa’ theory posits that modern humans first originated in East Africa between 4,00,000 and 3,00,000 years ago. It is believed that these early humans replaced archaic humans, and then dispersed to Europe and Asia to become the human populations that we know today.

Out-of-Africa Dates Pushed Back?

Did this dispersal happen in a single wave or multiple waves? When did modern humans first reach the subcontinent from Africa?

On 1 February, a study published in the journal Nature reported discovery of tools from the Middle Palaeolithic (2,00,000 to 40,000 years ago) at a prehistoric site, Attirampakkam near Chennai.

Archaeologist Shanti Pappu and her team from Sharma Centre for Heritage Education analysed close to 7,200 artefacts from between 3,85,000 and 1,72,000 years ago, and found traces of an advanced tool-making culture existing in India – well before the 140,000-year mark – at which a wave of migration from Africa was thought to have brought these technologies to India.

The artefacts suggest the possibility of ancient human species in India using similar techniques to those found in Africa prior to their migration out.

This discovery of stone tools carved by early humans in India could, thus, rewrite the origins of modern humans in India.

The treasure trove could also deepen the view on how early humans may have left Africa – much earlier than has been believed so far.

Here’s everything you need to know about the findings of the research, its implications for India, and the rest of the world.

What Does The Study Say?

The first hominins or early humans to leave Africa made use of oval-and pear-shaped hand axes and bulky cleavers to pound and scrape food using the Acheulian technique of toolmaking, which involved hammering a flint into a particular shape. After the British geologist Robert Bruce Foote discovered the archaeological site of Attirampakkam, 60 km from Chennai, in 1863, excavations at the site suggested that earliest tools at the site belonged to this Acheulian culture, Indian Express reported.

However, as per the latest study led by Kumar Akhilesh and Shanti Pappu from the Centre, tools unearthed from the sediments above the Acheulian soil layers belong to the time span – 3,85,000 to 1,72,000 years – and had traces of smaller, sophisticated tools than the earlier used bulky hand-axes. 

To find out the date of the fossil fuels, archaeologists made use of the infrared-stimulated luminescent technique only to find out that the last time sediment grains were exposed to light was between the said time span.

They found that the tools were made in the Levallois technique, an advanced technology that used fancy new blades, distinctive flaking, pointing methods, and thin stone flakes that could have tipped spears, National Geographic reported.

It has otherwise been associated with Neanderthals and Homo sapiens in Europe, the Middle East and Africa.

Hence, this study challenges the view, backed by the researchers, that modern humans brought this technology to India less than 1,40,000 years ago, coinciding with homo sapiens’ migration from Africa.

Instead, the detection of the Levallois technique at the new site suggests that it had existed in India well before the time period it was previously believed to have arrived, along with a migration of modern humans from Africa.

The Implications for India

The study’s discovery had opened the doors for two implications for India. First, it suggests that early humans may have left Africa, either in single or multiple waves of migration, much earlier than has been believed so far.

Due to this migratory move, modern humans could have arrived in India with newer techniques earlier than already known. This finding can act as a potential breakthrough in understanding of the evolution of the human species, the Indian Express report added.

Secondly, the presence of an advanced toolmaking culture in the site’s soil layers is likely to push back the date for the origins of Middle Palaeolithic technology in India from the traditionally defined time period.

According to earlier evidence, the Middle Palaeolithic culture in India was dated to have existed around 1,25,000 years ago. The new study, however, states that the “processes signify the end of the Acheulian Culture and the emergence of a Middle Palaeolithic Culture occurred 3,85,000 years ago and continued at Attirampakkam until 1,72,000 years ago.”

What’s So Great About the Middle Paleolithic Age?

This period holds significance (for us, anyway!) since it marks the origin of Homo Sapiens, or modern humans, who started using the Levallois technique.

The Middle Palaeolithic age is the second subdivision in the three-age system of archaeology and spans from 3,00,000 to 30,000 years ago.

Its culture initially consisted of “archaic” humans – an early branch of our species that included Homo rhodesiensis, Homo heidelbergensis, Homo antecessor, and Neanderthals, Gizmodo reported.

The archaic humans, also known as ‘early humans’, used the Acheulian technique to prepare tools – bulky hand-axes and stone cleavers – as part of their work.

The oldest Attirampakkam artefacts, earlier found at the site by the Centre’s researchers, were made using the Acheulian culture of Lower Paleolithic stone age dating back to 1,50,000 years ago. They were believed to have been crafted by archaic humans.

While early humans gradually became extinct, some interbred with Homo Sapiens or anatomically modern humans. They eventually adapted to the Levallois method, a newer, more sophisticated toolmaking technique.

Unlike the Acheulian technique, the Levallois technique required much closer foresight, detail and planning than the former.

The Levallois tools required two stages of construction, “hand carving a flint core into a specific shape, and then detaching the core with a single decisive strike,” the Gizmodo report added, whereas the Acheulian technique uses only one stage.

Also Read: Archaeologists Unearth Mummies From An Ancient Egypt Necropolis

By studying the site’s tools, the researchers documented a gradual shift away from the use of Acheulian large-flake technologies, towards the use of Levallois flake and point strategies.

The transition from the Lower Paleolithic Acheulian culture to the Middle Paleolithic in India is likely to be a result of the adaptation of the advanced technique.

Who Made These Tools?

Archaeologists in the past have found traces of Middle Paleolithic tools at sites across Africa, Europe, and the Middle East. India has not been isolated from this process. But the paucity of archaeological evidence on fossils in India leaves the tool-creators shrouded in mystery, the NPR report added.

A Middle Palaeolithic tool found at Attirampakkam.

Co-author Shanti Pappu said that no hominin fossil remains have yet been found at the site, so the answer on who made those tools using the advanced technique remains shrouded in mystery.

Now our data shows this might have happened even earlier… The question is, who made these tools? And the answer is, we don’t know. We don’t have hominin samples in India.
Professor Pappu Sharma 

The study also clearly states that the Middle Palaeolithic findings at Attirampakkam cannot be linked to a specific hominin species – whether archaic or modern humans – due to the paucity of evidence in India on fossil or genetic evidence for the said time period, the Indian Express report said.

Mysteries Remain Unanswered

Professor Pappu believes that the “number and nature of dispersals of populations bearing a Middle Palaeolithic culture from Africa is not a simple, linear model but is far more complex,” the Hindu reported.

Likewise, questions still remain unanswered on whether the Middle Paleolithic culture emerged within India on its own or was triggered by external forces such as interbreeding of archaic humans with modern humans, the Gizmodo report stated.

A criticism of the study is that other dating techniques than using just one dating method, ie: The luminescence method, could have been used to validate the findings.

Also Read: NASA to launch GOLD mission to study Earth's boundary with space

Are Experts United?

Far from it. Experts have been divided over the authenticity of the study’s findings. Many have acknowledged the study’s claims on dispersal of humans from Africa earlier than previously believed. But many are not yet convinced and want to wait for more discoveries to come up to corroborate the findings.

John Hawks, a paleoanthropologist at University of Wisconsin-Madison, said that earlier claims of modern humans in Africa leaving because of a ‘technological advantage’ stands false, crediting the study.

We used to think that modern humans spread from Africa because they had some enormous technical advantage that let them replace ‘stupid’ archaic humans; we now know this is false.
John Hawks to National Geographic

For paleoanthropologist Rick Potts, the head of the Human Origins Program at the Smithsonian Museum of Natural History told NPR that the “findings of the study clearly knock those ideas out of the water,” suggesting that migration from Africa happened earlier than has been believed till now.

Michael Petraglia, at the Max Planck Institute for The Science of Human History, touts the study as “a marvellous discovery in our knowledge of cultural history of humans in South Asia between 4,00,000 to 1,75,000 years ago.”

However, Alison Brooks, another paleoanthropologist from George Washington University, is far from convinced about whether smaller tools described by Pappu and her colleagues are true Levallois points, the Washington Post stated. She wishes for more discoveries to contextualise the findings. “It’s still basically a single point in a giant continent,” she added.

Ashok Singhvi, head of the Physical Research Laboratory in Ahmedabad told Indian Express that answers still need to be sought as to how humans, who came from Africa, spread out in India rapidly.

Firstly, were people evolving in different places, able to produce the same technology at the same time? Secondly, if a man came from Africa, how and when did he spread out so rapidly? We need to look at more sites in India, and the journey in between. The whole story will take many years to uncover.
Ashok Singhvi told the Indian Express

Pappu also shares similar concerns and will soon expand the study to take a new look at the other regions in India, the Washington Post stated. “They also have a story to tell,” she said.

(With inputs from Gizmodo, Indian Express, Washington Post, The Hindu, NPR, National Geographic)