But the new discovery of a bone near Johannesburg bolsters arguments that many cancers have a deep evolutionary history and are caused by factors beyond the control of humans.

A team of researchers from the Universities of Central Lancashire and Witwatersrand were scanning the fossils of prehistoric humans, which were found in the Swartkrans archaeological site, when they noticed that the inside of a toe bone was opaque.

“It was one of those moments when the light bulb goes on,” said Dr Patrick Randolph-Quinney, biological and forensic anthropology expert at Central Lancashire.

“The bone should have been hollow, and for it not to be hollow requires an expansion of some sort.

“So we compared it with modern biopsies of cancer patients and realised it was a malignant tumour.”

“We don’t know whether it was the cancer that killed him or something else.