Arabia has been green for long spells in the past 8 million years

Today Arabia is a scorching desert, but it has been green and lush several times in the past 8 million years. That means animals from Africa could have wandered into the area – potentially including early human relatives that were thought to have been confined to Africa.

“The deserts are turning on and off through time,” says Michael Petraglia at Griffith University in Brisbane, Australia. “We have hippos coming out of Africa. Why not hominins?”