Someone who just speaks English would have a hard time guessing that "oupa" in Greek, "Schwanz" in German, or "queue" in French all mean the same thing as "tail" in English.
The statistical correlation between the frequency of word use and its "mutation" is extremely high, the authors said.
"The relationship explains 50 percent of the variation in replacement rates between different words, a level of statistical power rarely observed in the social sciences," said Tecumseh Fitch of the University of St. Andrews, Scotland.
In a parallel study also published in Nature, Erez Lieberman, an evolutionary biologist and mathematician at Harvard University, probed changes over time in English verbs, especially the transition from irregular to regular verbs.
In Old English, changes in tense rarely adhered to specific rules, but gradually these "irregular" verbs have become standardized.
Lieberman and his colleagues, looking at 177 verb forms, show a mathematically exact link between frequency of use and change.
They found that a verb used 100 times more often than another will regularize 10 times more slowly.
Though they use very different methods, both papers arrive at the same conclusion: frequently used words are resistant to change.
Exactly why this relationship holds, however, is unclear.
One possibility, according to the researchers, is that new variations — or mutations, in the language of evolutionary biology — are rarer with commonly used words because people using them are less likely to make mistakes.
Put simply, we best remember the words we use every day. Another explanation would be that all words breed new variants, uttered in error or on purpose.
But the chances that this pretender will survive and flourish are diminished if, like an introduced species, it has to fight against an established rival which dominates its habitat.
