Skin cancer has been found spreading among catfish in a freshwater lake that spans the US and Canada. It’s only the fourth transmissible cancer ever found in nature. That puts catfish in a very strange club, alongside Tasmanian devils, dogs and shellfish.
Why is this so rare? Cancer cells are fragile, foreign to the immune system, and almost never survive the jump between bodies. A microbiologist explains how it happens anyway, and what it reveals about human cancer, too.
We also examine how artificial intelligence can dramatically speed up the search for patterns in undeciphered ancient languages, such as Etruscan and Linear A.
Finally, we look at how refugee trauma echoes across the generations, through one century-spanning story from the Greek island of Lesbos.
