Languages spoken by billions of people across Europe and Asia are descended from an ancient tongue uttered in southern Europe at the end of the last ice age, according to research. The claim, by scientists in Britain, points to a common origin for vocabularies as varied as English and Urdu, Japanese and Itelmen, a language spoken along the northeastern edge of Russia. The ancestral language, spoken at least 15,000 years ago, gave rise to seven more that formed a Eurasiatic "superfamily", the researchers say. These split into languages now spoken all over Eurasia, from Portugal to Siberia. "Everybody in Eurasia can trace their linguistic ancestry back to a group or groups … living around 15,000 years ago, probably in southern Europe, as the ice sheets were retreating," Reading University evolutionary biologist Mark Pagel said. Linguists have long debated the idea of an ancient Eurasiatic superfamily, a controversial idea because many words evolve too rapidly to preserve their ancestry. Most have a 50 per cent chance of being replaced by an unrelated term every 2,000 to 4,000 years. But some words last much longer. In a previous study Pagel's team showed that certain words - among them frequently used pronouns, numbers and adverbs - survived for tens of thousands of years before other words replaced them. For their latest study Pagel used a computer model to predict words that changed so rarely that they should sound the same in the different Eurasiatic languages. They then checked their list against a database of early words reconstructed by linguists. "Sure enough," said Pagel, "the words we predicted would be similar, were similar." In Proceedings of the National Academy of Sciences the authors list 23 words found in at least four of the proposed Eurasiatic languages. Most are frequently used, such as the pronouns for "I" and "we" and the nouns "man" and "mother". But survival of other terms was more baffling. The verb "to spit" and nouns "bark" and "worm" had long histories. "Bark was really important to early people. They used it as insulation, to start fires, and they made fibres from it. But I couldn't say I expected 'to spit' to be there. I have no idea why," Pagel said. The team drew up a family tree of the seven languages. All emerged from a common tongue about 15,000 years ago, and split off into separate languages over the next 5,000 years.