We know where the world’s loneliest species came from

The so-called Devils hole pupfish survives within one of the driest places in the world, in the heart of the Mojave desert in the US.

Each fish is less than one inch-long (2.5cm), and perhaps fewer than 50 individuals survive.

Even more remarkably, every member of this species has existed in the wild, since they first appeared thousands of years ago, within an area no bigger than the living room in your house.