A recent discovery has led scientists to believe that cancer may be an inherent part of the human evolutionary process. An analysis of a foot bone and a vertebrae of an extinct hominid found in South Africa revealed the oldest dated tumors ever found in human subjects. At 1.7 million years old, these fossils predate the earliest evidence of cancer by an estimated 200,000 years. The discovery was published Thursday in the South African Journal of Science.

The tumor belongs to a young male, estimated to have been developmentally equivalent to a modern day 12-year-old boy when he died. His cancer was not environmentally caused — most cancers found in ancient bones are osteogenic cancers, which is a cancer that starts in the bone.

The fossils are shocking in that scientists had assumed cancer was a more recent development. The oldest description of cancer dates to 3000 B.C.E. in an Egyptian textbook that describes cancer tumors as a disease with no treatment.

“This kind of research changes perceptions of cancer,” co-author Patrick Randolph-Quinney told CNN. “The takeaway is the notion that cancer is a huge continuous problem in the developed world, even if we have very healthy, perfect lifestyles we still have the capacity for cancer.”

The comparative size of the foot bone to the foot.
The comparative size of the foot bone to the foot.

The discovery is groundbreaking, say the researchers, because when you compare the cancer in this ancient fossil to a modern human osteosarcoma specimen, you can’t tell the difference.

Co-author Edward J. Odes stumbled on the tumor when he decided to further examine some bone samples discovered in Malapa, South Africa, 50 years ago. He used high-tech scanning techniques to get a closer look at the small piece of foot bone — a zoom in revealed that the cavity of the bone was actually filled with new bone formation. This abnormality led Odes to show the discovery to his fellow researchers, who got the hunch there was something more to the fossil.

Today, cancer is the second leading cause of death in the United States. We now know that it’s been a spectral presence over human evolution for millions of years; here’s hoping this discovery will lead to the death of that trend.

Photos via Wits University (1, 2, 3)

Sarah is a writer based in Brooklyn. She has previously written for The New Republic, Pacific Standard, and McSweeney's Internet Tendency. She likes cheese especially when paired with a full-bodied joke.