What can we learn about our evolutionary past from the microscopic remnants of protein found in the bones and teeth of ancient humans? Researchers are now using a technique called proteomics to identify the proteins that make up our predecessors’ bodies. The findings could provide insights into the past two million years of humanity’s history.
By analyzing these proteins, scientists hope to solve major evolutionary mysteries such as the identity of the common ancestors of Homo sapiens and the Neanderthals. Proteomics could have the same impact on our understanding of human history as the recent development of ancient DNA analysis, which has uncovered secrets about humanity’s past, including the discovery that many modern humans possess Neanderthal genes.
The UK is now leading the way in the field of proteomics, with a project launched by a team of scientists based at the Francis Crick Institute and the Natural History Museum. Over the next three years, they will assess how much protein can be obtained from fossils and what can be learned from the samples. “Hopefully, it will indicate we can learn a lot about our past by studying ancient proteins,” said Professor Chris Stringer of the Natural History Museum.
Part of the research will involve a handheld scanner that can be passed over a fossil to reveal how much protein it contains. “In that way, we can focus on only the most promising skulls and bones,” said Stringer. “It is crucial we don’t try to take samples – no matter how small – from fossils that have no protein to offer us for study.”
Proteomics is an advancement in the study of human evolution because DNA is fragile and decays fairly quickly, especially in warm conditions, making it mainly useful for studying fossils that are less than 100,000 years old and found in moderately cool or cold places. In contrast, proteins survive longer in warm conditions, allowing scientists to gain new insights into several baffling newly discovered species, including Homo naledi and Homo floresiensis.
However, proteins do not carry nearly as much information as DNA, containing only about 1% of the maximum information that could be obtained from a DNA sample. This means that scientists will need a lot of data to carry out meaningful analyses. Nevertheless, proteomics has already produced early promising results. Studies have shown that collagen proteins found in a piece of hominin jawbone at Baishiya Karst cave high on the Tibetan plateau in China match those of Denisovans.
“This is the first hint at what a Denisovan might have looked like and suggests that proteomics has a lot to offer our understanding of human evolution,” said Frido Welker of the University of Copenhagen. “It is certainly encouraging.”
Proteomics has the potential to unlock many of the secrets of human evolution, providing us with a better understanding of our past and how we came to be the species we are today.