Like in New Zealand, for example, tons of iconic animals like the Kiwi are threatened by introduced predators, including stoats, which are, like, this cute furry little weasel.
So individuals with mutations that reduced the length of their tails became more successful at life on land, surviving long enough to pass their short tails on to the next generation.
The quokka, an Australian marsupial about the size of a domestic cat, has full cheeks and a curved mouth that convey the impression-often to delighted tourists-that the critter is smiling.
The popularity of the quokka selfie has given us the opportunity to be able to raise awareness about the quokka's particularly on the mainland that are under threat.