Homo Naledi Fossil In Rising Star Cave Could Represent First Gender-Specific Burials By A Nonhuman Species

Jan Bartek - AncientPages.com - Scientists have extracted and analyzed the first-ever ancient proteins from the fossils of Homo naledi, revealing a potential all-female burial site.

The study, published in Cell, suggests that South Africa’s Rising Star Cave system may be the first known sex-specific burial site attributed to a non-human species.

Homo naledi, an extinct relative of modern humans that lived between 335,000 and 241,000 years ago, has puzzled researchers since its discovery in 2013. The species displays a unique combination of primitive, ape-like and human-like traits.

For over a decade, scientists have questioned why adult fossils from the cave’s Dinaledi Chamber appear so similar, showing little of the physical variation typically seen between males and females.

To address this question, researchers from the University of York, the University of Copenhagen, the National Geographic Society, and more than 10 other international institutions analyzed proteins extracted from the skeletal remains.

Using a minimally destructive acid etching technique, the team extracted microscopic protein fragments, or peptides, from 23 teeth representing at least 20 individuals.

Researchers analyzed the tooth enamel for Amelogenin-Y, a protein uniquely coded by the male Y chromosome.

The results showed the male marker was absent. To confirm these findings, a team at the University of York’s specialized chemistry facility analyzed the amino acids to verify that the proteins were genuinely ancient and not the result of modern contamination.

Dr Marc Dickinson, from the University of York’s Department of Chemisty, said: “The lack of male markers with the group is truly fascinating. It is incredibly exciting to gain a window not only into the biology of our ancestors, but also into how they lived.

“These findings offer rare insights into a culture that has, until now, been difficult to access directly. Advances in ancient protein analysis are opening the door to a far richer and more nuanced understanding of ancient hominins.”

Homo naledi facial reconstruction. Credit: Cicero Moraes (Arc-Team) et al. ii - CC BY 4.0

The findings raise new questions about the culture and social structure of these ancient hominins. If the chamber was reserved only for females, it may suggest a complex, symbolic mortuary practice previously thought unique to Homo sapiens.

The team noted that a biological explanation is also possible. The Homo naledi population may have been highly isolated, which could have led to mutation or deletion of the male-specific Amelogenin-Y gene.

This suggests that males were present, but their teeth did not display the usual genetic markers.

Palesa Madupe, who completed the work as part of her postdoctoral research at the University of Copenhagen, said: “Unlike those found in other remains like bone fragments, proteins in tooth enamel are preserved because dental enamel – the hardest tissue in the human body – shields proteins from environmental contamination even for millions of years.

See also: More Archaeology News

“This makes them ideal carriers of genetic information from deep time. Our study helps in the long-standing mystery of why Homo naledi lacked significant variation; it’s probably because they could have all belonged to one sex.”

As the largest extinct hominin population analyzed for proteins, these ancient females or genetically distinct males have led scientists to reconsider previous assumptions about early human society.

The study was published in the journal Cell

Written by Jan Bartek - AncientPages.com Staff Writer