Tasmanian devil cancer
[Weird medical shit]
I read about this medical phenomenon recently that I found incredible: a new pathogen that seemed to be causing facial tumors in Tasmanian devils. It turned up in the mid 90s, and at first they thought it was a virus. Turns out, a Tasmanian devil got cancer in the face, and because Tasmanian devils bite each other all the time, the original cancer is now travelling throughout the population.
To me, this is staggering. I've never heard of anything like this before. I was taught about the regular pathogens of bacteria, fungi and viruses, but as far as I'm aware this kind of pathogen is entirely new. What do you even call that? Suppose you left it unchecked for thousands of years (and also suppose it didn't wipe out the Tasmanian devils), it'd evolve to be a better pathogen. And the Tasmanian devils would evolve defences to it. That freaks me out. Does it count as a new species?