Homo Naledi: Burial Ritual Controversy

In the dark, twisting tunnels of the Rising Star Cave system in South Africa, a scientific battle is currently unfolding. At the center of this storm is Homo naledi, an ancient human relative with a brain the size of an orange. Paleoanthropologist Lee Berger and his team made headlines in 2023 with explosive claims that this small-brained species buried its dead and carved symbols onto cave walls. These behaviors were previously thought to be exclusive to large-brained hominins like Neanderthals and Homo sapiens. However, the scientific community has pushed back hard, arguing that the evidence does not support these sensational conclusions.

The Claims: Burial and Art

The controversy centers on three preprint papers released by Berger’s team in June 2023. They argued that Homo naledi, which lived roughly 250,000 years ago, engaged in complex cultural practices.

Deliberate Interments

The team identified shallow, oval-shaped pits in the Dinaledi Chamber and the Hill Antechamber of the cave system. They claimed these pits contained the skeletal remains of Homo naledi individuals arranged in fetal positions. According to Berger, the soil layers (stratigraphy) showed clear signs of disruption, indicating that holes were dug, bodies were placed inside, and then covered with dirt. This would mark the earliest known example of burial by a hominin species.

Rock Engravings

Alongside the burials, the researchers described cross-hatchings and geometric shapes etched into the dolomite walls of the cave. These engravings include hashtags and lines similar to art found in Neanderthal sites. The team argued that because Homo naledi is the only hominin found in the cave, they must be the artists.

Control of Fire

To navigate the pitch-black, narrow chutes of the Rising Star system, the team asserted that Homo naledi must have mastered fire. They cited evidence of soot on the cave ceilings and hearth-like areas, suggesting these creatures walked through the darkness with torches to perform their mortuary rituals.

The Scientific Backlash

The excitement surrounding these announcements was dampened quickly by the peer review process. The papers were submitted to the journal eLife, which uses a transparent review system. The peer reviewers, including experts in biological anthropology and archaeology, rejected the claims in their initial state. They labeled the evidence as “inadequate” and “incomplete.”

Critique of the Burials

Reviewers pointed out significant flaws in the excavation methodology.

• Lack of Excavation: Critics noted that the researchers did not actually fully excavate the alleged burial pits to confirm they were dug holes.
• Natural Formation: Experts like María Martinón-Torres from the National Research Center on Human Evolution (CENIEH) in Spain argued that the bone positions could be the result of natural decomposition or water movement.
• Missing Stratigraphy: The published papers lacked detailed geological maps proving that the soil layers were cut and filled by ancient hands.

Critique of the Cave Art

The skepticism regarding the wall engravings is even stronger. The primary issue is dating.

• No Direct Dating: The team did not date the engravings themselves. They assumed the art was associated with the bones because they were in the same cave.
• Modern Interference: Critics pointed out that the engravings look fresh and unpatinated. Without radiometric dating or sediment analysis, the marks could have been made by modern cavers or prospectors decades ago.
• Interpretation: Michael Petraglia from Griffith University noted that mere proximity to fossils does not prove authorship, especially without a confirmed timeline.

The Netflix Factor

A major point of contention was the timing of the media release. The claims were featured prominently in the Netflix documentary “Unknown: Cave of Bones,” which premiered in July 2023. This documentary presented the burial and art hypotheses as established facts.

Many scientists criticized this approach. They argued that releasing a polished documentary before the scientific papers passed peer review undermines public trust in science. It creates a narrative that science is about dramatic reveals rather than rigorous data verification.

Why This Debate Matters

The stakes in this controversy are incredibly high for our understanding of human evolution. For decades, the prevailing theory has been that “big brains” are required for complex emotional and symbolic behavior (like mourning the dead or creating art).

If Homo naledi truly performed these rituals with a brain one-third the size of a modern human’s, it would force a rewrite of anthropology textbooks. It would imply that cognitive complexity is not strictly tied to brain volume.

However, extraordinary claims require extraordinary evidence. As of late 2023 and early 2024, the consensus among outside experts is that the current data does not support the conclusion of deliberate burial or rock art. The burden of proof remains on Berger and his team to produce clearer dates, better soil analysis, and more rigorous excavation data to convince the scientific community.

Frequently Asked Questions

Did Homo naledi definitely bury its dead? No. While Lee Berger and his team claim they did, peer reviewers found the evidence inconclusive. Natural processes like water flow or soil shifts could explain the position of the bones.

How big was the brain of Homo naledi? Their brains were approximately 450 to 600 cubic centimeters. This is roughly the size of an orange, or similar to the brain size of a chimpanzee or Australopithecus.

Where were the fossils found? The fossils were discovered in the Rising Star Cave system in South Africa, specifically in the Dinaledi Chamber, which is extremely difficult to access.

Has the cave art been dated? No. The engravings on the cave walls have not been directly dated. Critics argue they could have been created by modern humans entering the cave in the last century.

What is the “Unknown: Cave of Bones” documentary? It is a Netflix film released in July 2023 that follows Lee Berger’s team. It presents the burial and art claims as facts, which caused controversy because the scientific papers had not yet passed peer review.