In the beginning was the word. And it was first spoken by Homo erectus, according to a controversial new theory.
Most palaeoanthropologists believe language emerged with the evolution of Homo sapiens around 350,000 years ago. But Daniel Everett, professor of Global Studies at Bentley University, Massachusetts, and author of How Language Began, claims our earlier ancestors must have been able to talk to each other.
Everett claims that Homo erectus, who lived from 1.9 million years ago, invented language and used it to help build boats to colonise remote islands such as Flores in Indonesia and Crete, where fossils have been found even though there were never land links with Africa.
Speaking at the American Association for the Advancement of Science annual meeting in Austin, Texas, he said: "Everybody talks about Homo erectus as a stupid ape-like creature, which of course describes us just as well, and yet what I want to emphasise is that erectus was the smartest creature that had ever walked the Earth.
"They had planning abilities. They made tools.
"But the most incredible tools that erectus made were vessels for sailing the open ocean.
"Oceans were never a barrier to the travels of erectus. They travelled all over the world. They needed craft and they needed to take groups of 20 or so at least to get to those places.
"Erectus needed language when they were sailing to the island of Flores. They couldn't have simply caught a ride on a floating log because then they would have been washed out to sea.
"They needed to be able to paddle. And if they paddled they needed to be able to say 'paddle there' or 'don't paddle'.
"You need communication with symbols, not just grunts. They accomplished too much for this to simply be the sort of communication that we see in other species without symbols."
Homo erectus was the first member of our genus Homo, and so was the first species of human. It stood up to 180cm tall, and had the biggest brain of any land animal that had lived, around 950cu cm, roughly the size of European females' brains today.
"They certainly were not incapable of speech, they just would have had a different speech," said Everett.
However, Professor Chris Stringer from the Natural History Museum in London, was sceptical about the claims.
"I don't accept that, for example, erectus must have had boats to get to Flores," he said. "Tsunamis could have moved early humans on rafts of vegetation. That said, I think Homo heidelbergensis [who lived between 600,000 and 200,000 years ago] had a complex enough life to require speech, though not at a level of modern human language.
"With erectus, I'm not so sure."