Full Breakdown
All Known Homo naledi Specimens Appear Female, Raising Questions About Sex-Specific Burial Practices
6/26/2026, 4:05:15 AM
Core Findings
Proteomic analysis of 23 teeth from at least 20 Homo naledi individuals found only the X-linked amelogenin (AMELX) and no Y-linked amelogenin (AMELY), indicating all sampled specimens are female.
Context of Discovery
The fossils were first uncovered in 2013 by Lee Berger’s team in the Dinaledi Chamber of Rising Star cave, part of South Africa’s Cradle of Humankind, dated to late Pleistocene, 335–236 kyr.
Key Researchers
Lead author Palesa Madupe (Max Planck Institute) oversaw protein extraction; co-authors include Lee Berger (Witwatersrand), John Hawks (Wisconsin-Madison), Enrico Cappellini (Copenhagen), and Marc Dickinson (York).
Proteomic Results and Statistics
The analysis identified AMELX in every tooth and detected no AMELY in any of the 20 individuals. Nineteen were classified as female with >95 % probability; the twentieth also matched a female profile. Random sampling of 20 females from an even sex ratio has a probability of 0.0000954 % (?1 in a million), low indeed.
Significance for Hominin Behavior
The female signature suggests a sex-specific mortuary practice, possibly the earliest known for a hominin. This may explain low morphological variation and challenges the idea that complex burial needs a large brain.
Official Interpretations
Berger calls result evidence of cultural selection after death for burial by sex. Hawks notes assemblage predates known Neanderthal or modern human burial site, highlighting its uniqueness. Cappellini says a systematic AMELY deletion across population is improbable. Madupe says findings resolve variation puzzle by attributing it to a single sex.
Scholarly Critique
Emma Pomeroy warns issues could create pattern. Bernard Wood argues depositing bodies through chute is not burial. Kimberly Foecke notes geometry may have limited male access, biasing sample. Michael Petraglia suggests a female-to-male ratio in group, and Eric Crubézy says females make demographic slice unlikely.
Unresolved Issues
Some authors suggest an AMELY gene deletion or degradation could mask males. Teeth were analyzed, so sex of individuals lacking dental material remains unknown. Morphology of “Neo” specimen is uncharacterized.
Verbatim Quotes
- “The most likely reason for these robust results are, in my opinion, cultural selection after death for burial by sex and perhaps gender,” — Lee Berger, paleoanthropologist
- “Our study helps resolve the long-standing mystery of why Homo naledi lacked significant variation; it’s probably because they could have all belonged to one sex.” — Palesa Madupe, lead author
- “These remains of Homo naledi are older than any known Neanderthal or modern human burial site, and it’s remarkable to see that they may all be female.” — John Hawks, co-author
- “it's very unlikely that this would be the case among even half of the 20 individuals we studied or for an entire population,” — Enrico Cappellini, paleoproteomics professor
- “The lack of male markers with the group is truly fascinating.” — Marc Dickinson, fossil chemist
Future Directions
Future work will apply the acid-etch proteomic method to other African hominin fossils, expand the protein reference database, and search for additional sites that might contain male remains.
