What the 1997 study did not, and could not, tell anyone was anything about what Cheddar Man looked like. That would have to wait for a different kind of analysis.
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## The Long Wait and the Petrous Bone
Ancient DNA research advanced dramatically in the years following the Sykes team’s 1997 mitochondrial study. The development of more sensitive sequencing technologies, better laboratory contamination controls, and more sophisticated computational methods for assembling degraded DNA fragments into coherent sequences made it possible to work with genetic material that earlier methods would have dismissed as unrecoverable.
A key insight that improved ancient DNA recovery rates significantly was the identification of the petrous bone — a part of the temporal bone at the base of the skull that forms the bony housing of the inner ear — as an unusually reliable source of ancient genetic material. The petrous is one of the densest bones in the human body. Its density offers some protection against the microbial and chemical processes that degrade DNA over time. Studies comparing DNA recovery rates from different skeletal elements found that the petrous bone consistently yielded higher quantities of better-preserved ancient DNA than other bones, including the teeth and long bones that had previously been preferred sources.
This technical development, combined with the improved sequencing methods that had emerged in the early twenty-first century, made a comprehensive genome sequencing of Cheddar Man newly possible around the middle of the 2010s.
A collaboration between researchers at University College London and the Natural History Museum set out to do exactly that. The project brought together researchers in ancient genomics, population genetics, and human evolution to produce what would be described at the time as the oldest British whole genome ever sequenced.