There’s no foolproof way to avoid extinction. A disease, a global cold snap, an asteroid with a deadly trajectory – these are all things that every other species in the entire history of life hasn’t been able to foresee or plan for. One day the world changes, and only the lucky survive.

But there are a few ways that entire lineages of organisms have inadvertently made themselves resistant to extinction. One of the best, it seems, is to spread far and wide over the planet. At least then there’s a chance that some members of the family will persist in a refuge, able to stick it out through the worst of the extinction pulse.

This is just the sort of good fortune