Because words don’t have DNA, researchers use cognates found in different languages today to reconstruct the ancestral “protowords.” Historical linguists have observed that over time, the sounds of words tend to change in regular patterns. For example, the p sound frequently changes to f, and the t sound to th—suggesting that the Latin word pater is, well, the father of the English word father. Linguists use these known rules to work backward in time, making a best guess at how the protoword sounded. They also track the rate at which words change. Using these phylogenetic principles, some researchers have dated many common words as far back as 9000 years ago. The ancestral language known as Proto-Indo-European, for example, gave rise to languages including Hindi, Russian, French, English, and Gaelic.
Some researchers, including Pagel, believe that the world’s languages are united by even older superfamilies, but this view is hotly contested. Skeptics feel that even if language families were related, words suffer from too much erosion, both in terms of sound and meaning, to be reliably traced back further than 9000 or 10,000 year, and that the similarities of many cognates may be pure chance. What was missing, Pagel says, was an objective method of analysis.
Story: Elizabeth Norton, Science Magazine | Photo: Wikimedia Commons