Before our ancestors even existed, ancient hominins might have been sailing the seas and discovering new lands. This, according to one researcher, suggests they were also talking to each other as a result.

It's generally believed that language first evolved with our own species around 300,000 years ago, although there's some evidence to suggest that Neanderthals may have been able to speak as well. Now, researchers are questioning whether or not language might have evolved much earlier than this.

When our own species stepped out of the African continent, we were following in the footsteps of another ancient hominin. Homo erectus is thought to have evolved roughly 1.9 million years ago in Africa and is the first to have had itchy feet. By 500,000 years ago, the ape had made three expansions out of the continent, making it to southern Europe, China, and even several Indonesian islands.

It's this last feat that has intrigued paleoanthropologists.

Fossils show that the ancient human managed to make it to Java by around a million years ago, with some suggesting they then crossed the open water to reach the island of Flores. It's also been argued that the diminutive hominin Homo floresiensis is descended from H. erectus, but this is a highly contentious point, with some evidence suggesting otherwise.

“Oceans were never a barrier to the travels of erectus,” Daniel Everett, who presented the new thorey, told the American Association for the Advancement of Science meeting this week. “He travelled all over the world, travelled to the island of Flores, across one of the greatest ocean currents in the world. They sailed to the island of Crete and various other islands. It was intentional: they needed craft and they needed to take groups of 20 or so at least to get to those places."

He argues that in order to cross the turbulent waters around Indonesia, they would have needed to have built vessels and coordinate paddling. This, he says, is simply not possible without some form of rudimentary language.  

While interesting, this is not exactly a widely accepted theory. Some do agree that if H. erectus built boats, they would have been able to communicate in more than just grunts, but others question if they even built vessels. Monkeys, for example, are not known for their sea-faring ability and yet they made it across the Atlantic from Africa to South America 40 million years ago.

Just because Homo erectus could craft tools does not mean they had language. Plenty of animals – from chimpanzees to Caledonian crows – are able to manipulate objects and make tools without anywhere near the same word skills that we employ. This ability alone, then, is not sufficient to conclude with confidence that H. erectus could talk too.