Thanks to a lack of evidence, the history of cancer is often wrought with debate. But scientists have now found the oldest example of human cancer in a 1.7-million-year-old bone, National Geographic reports. Scans of the fossil, a toe bone from South Africa, revealed a malignant tumor on the left foot of an unknown human relative. Researchers diagnosed the tumor as the aggressive bone cancer osteosarcoma. A second fossil in a separate paper, from a 1.98-million-year-old Australopithecus sediba, revealed the oldest known benign tumor. Together, say scientists, these fossils show that even if the modern world has higher rates of cancer, the triggers for the disease are found somewhere within our evolutionary past.