Researchers from Cambridge have traced the world's oldest known cancer back to 11,000 years ago. And this strain of cancer is unusual, and exceptionally creepy, because it's a sexually transmissible form of cancer carried by dogs.
Canines can pass along the "grotesque" genital cancer through sexual intercourse. (Via YouTube / Sue Hess)
The only other known animal species to carry transmissible cancer, as seen in this CBS video, is the Tasmanian devil — which can carry an aggressive facial cancer spread through biting.
In order to trace back the oldest recorded cancer case, researchers first hit the history books, then analyzed genomes from dogs currently suffering from this particular type of cancer.
"The genome of this cancer, which is living in all these dogs around the world today, is actually the same genome of the orginal dog that lived all those thousands of years ago." (Via The Wellcome Trust Sanger Institute)
The original dog is described as looking kind of like a husky with grayish-brown or black fur.
It's believed the cancer initially formed in an unknown isolated place and started migrating across the world about 500 years ago — the same period as the age of exploration for Europeans. (Via Wikimedia Commons / Shizhao)
Another pretty shocking revelation in the findings:
The majority of human cancers have about 1,000 to 5,000 different mutations. But in the transmissible cancer among dogs, there are almost 2 million known mutations. (Via National Cancer Institute , Wikimedia Commons / Jijipowa)
So what can we take from the findings? Well, according to one of the lead researchers: "The genome of the transmissible dog cancer will help us to understand the processes that allow cancers to become transmissible. ... Although transmissible cancers are very rare, we should be prepared in case such a disease emerged in humans or other animals." (Via University of Cambridge)
They also hope the findings will help them understand the evolution of cancer in more general terms.