Scientists have recovered ancient proteins from the teeth of Homo naledi for the first time, revealing evidence that the fossils discovered deep within South Africa’s Rising Star cave system may all belong to females.
The breakthrough study marks the first successful analysis of ancient proteins from Homo naledi, an extinct human relative whose remarkable discovery in 2013 transformed scientists’ understanding of human evolution. The findings also deepen the mystery surrounding how dozens of individuals came to rest in one of the most inaccessible cave systems ever associated with ancient human remains.
The international research team was led by molecular scientist Palesa Madupe and palaeoproteomics expert Professor Enrico Cappellini. Researchers worked closely with the National Geographic Society’s Rising Star project and its partner institutions.
By extracting and analysing preserved proteins from ancient teeth, the team was able to determine the biological sex of several individuals. The results suggest that the remains recovered from the cave chamber may all be female – an unexpected finding that raises fresh questions about the composition of the group and the circumstances that led to their deposition deep underground.
Homo naledi first captured worldwide attention following the discovery of more than 1,500 fossil specimens in the Rising Star cave system, part of South Africa’s Cradle of Humankind World Heritage Site. The fossils were uncovered through the Rising Star project, led by palaeoanthropologist Lee Berger, and represent one of the largest collections of fossil remains from a single ancient human relative.
The remote location of the bones, found hundreds of metres inside a complex cave network, has fuelled years of scientific debate. Some researchers have suggested the chamber may have been deliberately used to place the dead, while others argue that natural processes could explain the accumulation of remains.
The new protein analysis provides an important new tool for studying Homo naledi, whose fossils are often too old or poorly preserved for DNA analysis. Ancient proteins can survive far longer than genetic material, allowing researchers to investigate biological relationships, sex and evolutionary history even when DNA has degraded.
Although the discovery that the analysed individuals may all be female does not yet explain why the fossils accumulated in the cave, it adds another intriguing piece to one of palaeoanthropology’s most enduring puzzles. The researchers say further protein analyses of additional Homo naledi fossils will be needed to determine whether the pattern reflects the wider population or simply the individuals examined in this study.
The findings demonstrate the growing potential of palaeoproteomics to unlock new information from ancient human fossils, opening fresh avenues for research into the evolution and behaviour of extinct members of the human family.
Header Image Credit : Mathew Berger
Sources : Max Planck Institute for Evolutionary Anthropology
