Only a few years ago, scientists believed modern humans evolved in Africa, and then left to colonise a world free of similar species.

Recently, we have learnt this is not quite right. By the time Homo sapiens left Africa, several of our less-evolved ancestors had already travelled to parts of the world.

But it was not clear if these separate species – including Homo erectus, Homo luzonensis and Homo floresiensis – were alive at the same time, or if they were alive when modern humans left Africa.

A study by Australian scientists published in Nature on Thursday goes some way to answering that.