Using a unique new molecular fingerprinting technique, a team of scientists from Oxford University and Manchester University has identified a Neanderthal bone from approximately 2,000 tiny bone fragments. All of the fragments were retrieved from the Denisova Cave in Russia, a key archaeological site. The achievement marks the first time that scientists have gathered remains from an archaeological site and identified traces of an extinct human using the Zooarchaeology by Mass Spectrometry (ZooMS) technique.
The team examined a microscopic sample of bone from the site, which revealed the specific collagen peptide sequences in the bone that can eliminate certain species from the analysis. The study suggests that ZooMS could help us better understand numerous facets of human evolution, including interbreeding events that took place between our close relatives.
Analysis of the specific collagen peptide sequences in the bone revealed the differences in these patterns between animal species. After profiling sequences using samples from 2,300 unidentified bone fragments from Denisova Cave, the team compared the results to those contained in a reference database of peptides from known animal species, revealing that the piece of bone had a clear human fingerprint.
"When the ZooMS results showed that there was a human fingerprint among the bones I was extremely excited," said Samantha Brown, first author of the study. "After a lot of hard work, finding this tiny bone which yields so much information about our human past was just fantastic. The bone itself is not exceptional in any way and would otherwise be missed by anyone looking for possible human bones amongst the dozens of fragments that we have from the site."
The team discovered that the bone belonged to a Neanderthal, which was determined by examining its mitochondrial genome. The finding points to a close relation to other Neanderthals in the Altai region and was radiocarbon dated to be over 50,000 years old. Furthermore, acid etching on its surface reveals that it was likely consumed by a hyena before being buried deep in the sediments of the cave.
'This is a real breakthrough, showing that we can now use bioarchaeological methods like ZooMS to search the archaeological record and find even tiny fossil remains, where there are proteins that survive," said Thomas Higham, co-author of the study. "In the Palaeolithic period, where we have Neanderthals, Denisovans and modern humans, this is potentially very important because if the fragments that we recover are big enough then we can date and analyze the DNA from the same bone."
The findings were published in the March 29 issue of Scientific Reports.
