"Our studies show the origins of these diseases occurred in our ancient relatives millions of years before modern industrial societies existed," lead author Edward Odes, a University of the Witwatersrand doctoral candidate, said.
In an accompanying paper appearing in the same journal, a collaborating team of scientists identified a benign tumor in a two million-year-old fossil from Malapa, South Africa.
The benign neoplasm is the oldest tumor ever found in the human fossil record and was identified in the vertebrae of a child belonging to the ape-like hominin species Australopithecus sediba, well known for the famous 'Lucy' specimen.
It is not possible to tell the exact species to which the foot bone belonged, nor if it was an adult or child. The researchers are also unsure whether the osteosarcoma caused the death of the hominin.
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"We can tell this would have affected the individuals' ability to walk or run. In short it would have been painful," Bernhard Zipfel, a Wits scientist and an expert on the foot and locomotion of early human relatives, said.
The finding suggests that the mechanisms of malignancy have an extremely old evolutionary history.
"The capacity for malignancy is ancient, and the higher incidence of malignancy in today's developed and developing world may be related to the unique interaction between environmental factors – which have no parallel in prehistory," the researchers concluded.
They noted that advanced imaging techniques, together with an appropriate use of comparative clinical pathology, hold potential for re-investigating previously reported lesions in ancient fossils.
"It is possible that cases of malignancy might remain unknown in fossil assemblages awaiting imaging and discovery," the researchers said.