Koala

The marsupial may be a rare find in the wild these days, but they've nearly been wiped off the planet before. This study rewrites our understanding of the genetic history of koalas – and overturns the theories about what caused their ancient decline.

Australia's embattled koalas have been given some good news for once, with the approval of the world's first chlamydia vaccine. More than a decade in the making, a single jab will now protect koalas from the disease decimating their populations.