In September 2015 a barrage of publicity announced the remarkable unearthing of the remains of 15 diminutive hominins (see: The ‘star’ hominin of South Africa; September 2015). Subsequently this number rose to at least 24. It was named Homo nadeli, from the floor sediments of an almost inaccessible chamber in the Rising Star cave system of South Africa. In many respects the individuals seemed to share affinities with both australopithecines and the earliest known human, but subsequent dating to 335 to 236 ka proved they were not a ‘missing link’. Many near-complete skeletons suggested that they were similar in many ways to members of the genus Homo. Like H. floresiensis they may have evolved during protracted isolation from their contemporary hominins, perhaps even early modern humans. Nevertheless, it was indeed one of the most dramatic palaeoanthropological discoveries of the 21st century. But its celebrety is as much for the extraordinary efforts of women archaeologists small and lithe enough to wriggle through a maze of extremely narrow cave passages: and the deft PR skills of the leader of the discovering expedition, Lee Berger.
The skeletal remains in the remote chamber were near-complete, with little sign of physical trauma, except gnawing by snails and beetles. Few hominin bones have turned up in the more accessible parts of the cave. One likely explanation was that a living H. naledi group had deliberately carried the bodies through the cave system for burial – at less than 1.5 m tall with a slender build they could have done this far more easily than the modern excavators, but they must have used firebrands to light their way. It was alternatively suggested that a group of them, panicked by large predators, may have scrambled deep into the cave to hide, and suffocated as CO2 built-up to toxic levels, as happens occasionally to trapped speleologists. But another twist has arisen, more than a decade after the discovery.
Applying the large spectrum of modern forensic analysis to such a wealth of bones takes time. One approach, genetic sequencing, demands a great deal of patience. None of the bones preserved ancient DNA, probably because of their age and the high ambient temperatures and humidity of burial at low latitudes. A team led by Palesa Madupe of the Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany then resorted to extracting protein from tooth enamel of 20 individuals (Madupe, P. and 20 others 2026. Proteomic analysis of dental enamel from 20 Homo naledi individuals shows no male markers. Cell, v. 189, p. 1-10; DOI: 10.1016/j.cell.2026.05.044). One dental protein amelogenin (or AMEL) in every analysed hominin species has separate male and female types (AMELX and AMELY), analogous to Y and X chromosomes. Rather than being of mixed sex, the bodies were all women: even the few infants. So, what can that one-in-a-million finding imply?
One of the leaders of the Rising Star team (Lee Berger) had suggested since 2015 that H. naledi had purposefully buried its dead. He now suggests that the species separated sexes in their death rituals. For beings with brains about the size of chimps that seems unlikely to some critics. The earliest evidence for separate mortuary practices only appears in late-Neolithic burials. Moreover, the first evidence for any kind of human inhumation is about 100 ka later than Rising Star at a Neanderthal site in Israel. A possibly more plausible explanation is that H. naledi men were simply too big to reach the burial chamber, i.e. that the species was sexually dimorphic. If so, then why are there no remains of men in more easily accessed parts of the cave system? There remains one other scientific possibility: perhaps H. nadeli had only one type of AMEL and the genes responsible for it – i.e. the L variety was shared between both sexes. Palesa Madupe had previously found AMELY in tooth enamel from a 2 Ma-old South African hominin, so considers that possibility to be highly unlikely. All other approaches seem to be a matter of opinion about cultural practices of which we know little. One seems useful. If H. naledi had a high female to male ratio, perhaps females died at ‘home’, while male hunters were killed while hunting and then eaten by large predators … Further suggestions via Leave a comment.
See also: Gibbons, A. 2026. An ancient mystery: missing males. Science, v.392 News; DOI: 10.1126/science.aej9809; Barras, C. 2026. All known Homo naledi skeletons seem to be female. New Scientist; 24 June 2026.
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