Rising Star Cave

The existence of Homo naledi is broadly accepted. The Rising Star chambers yielded thousands of skeletal elements from many individuals, describing a genuinely mosaic hominin - some features primitive, some modern-like - with a brain roughly a third the size of ours, dated by multiple methods to the Middle Pleistocene. That such a small-brained species existed so recently, overlapping in time with early Homo sapiens elsewhere in Africa, is itself a significant finding.

The controversy is over behaviour. In 2023 Berger's team posted preprints, timed to a Netflix documentary and heavy press coverage, claiming deliberate burial and deliberate wall engravings. When the papers went through eLife's open peer-review model, the reviewers were sharply critical: they found the evidence for intentional burial inadequate and largely assumption-based, argued natural processes such as water action could account for the bone accumulations, and noted the engravings had not been directly dated or shown to be the work of naledi rather than later humans. A separate group of specialists published a formal rebuttal arguing there was no scientific evidence for advanced symbolic behaviour.

Berger's team revised and resubmitted; in the later review round the response was mixed, with some reviewers softening and others still unconvinced, particularly over how naledi could repeatedly reach so inaccessible a chamber. The mainstream position is that Homo naledi is real and important, but that the burial and engraving claims remain unproven and were announced with more publicity than the evidence justified.