During the Ice Age, our ancient ancestors communicated with long-forgotten languages. Now, though, new research has revealed that these people may have had several words in common with us. In fact, some of these words could still be recognized today.

Linguists have long sought the beginnings of language as they trace back the history of words through the years. Most languages actually evolve gradually over time as various populations of people diverge. Tiny variations, such as accents, can eventually become larger changes until a new language is formed. This means that researchers can essentially reconstruct these "root" languages by looking at the similarities between the modern languages of today.

Yet actually tracing back these languages can be extremely time-consuming. Previously, linguists have relied on studying shared sounds among words to identify those that are likely to be derived from common ancestral words. One example is the Latin "pater" and the English "father." The problem with this approach is that sometimes words can sound similar by accident.

Fortunately, researchers found a way to combat this problem. They discovered that subsets of words used frequently in everyday speech are more likely to be retained over long periods of time. Knowing this, they then predicted words likely to have shared sounds. This made it less likely that the words were similar by chance.

So what did the researchers find? Using statistical models, they discovered that certain words would have changed so slowly that they would have retained their ancestry for up to ten thousand or more years. The existence of these words actually points to the existence of a linguistic super-family tree that unites seven major language families, including Indo-European, Uralic, Altaic, Kartvelian, Dravidian, Chuckchee-Kamchatkan and Eskimo-Aleut.

"The way in which we use a certain set of words in everyday speech is something common to all human languages," said Mark Pagel, professor of Evolutionary Biology, in a news release. "We discovered numerals, pronouns and special adverbs are replaced far more slowly, with linguistic half-lives of one every 10,000 or even more years. As a rule of thumb, words used more than about once per thousand in everyday speech were seven to ten times more likely to show deep ancestry in the Eurasian super-family."

The research has important implications for understanding the evolution of human languages, and learning more about our roots. With these new findings, linguists could potentially reconstruct the ancient "mother" of all languages that was used in the very beginnings of human history.

The findings are published in the Proceedings of the National Academy of Sciences.