London, Jan : Languages, just like living organisms, change and evolve in quick bursts, rather than in a steady pattern, according to a new study.
The study, by Mark Pagel, an evolutionary biologist at the University of Reading, UK, and his colleagues, indicates that new words develop slowly most of the time, but with spurts of diversification when two languages divide.
Linguists have long known of specific cases in which the desire for a distinct social identity has caused languages to change quickly. But it has not previously been known whether such bursts of change are a regular feature of the evolution of human language.
Pagel and his team have found that branches heavy with linguistic divorces evolve faster, signifying 'punctuational bursts' of language change when two languages split.
The scientists estimated that the speedy change in these bursts form between 10 percent and 33 percent of total word differences between languages.
For the study, the team used a list of 200 everyday words to make a family tree, or phylogeny, of hundreds of modern languages. These 200 words were most likely all-identical in the first language, but modified to new forms in due course.
According to Pagel, he used the words "almost like a set of 200 genes" in which a change to a new form is like a mutation.
The scientists say that their findings show that modern languages that have broken up many times from other languages have accumulated more 'mutations', meaning that they are evolving faster.
Pagel believes that these mutations in all probability occurred in bursts of change right after the languages split.
"What we thought was quite remarkable is that the effect that is causing between a tenth and a third of changes is associated with relatively short periods of time around these splitting events. We think that it is quite a powerful effect," Nature quoted Pagel, as saying.
According to Pagel and his team, there are two possible reasons for such bursts in language evolution. One could be the founder events, in which the idiosyncrasies of a small number of language originators colour the language ever after, while the other cause could be the social desire of groups that have split off to separate themselves from the original language.
Brian Joseph, a historical linguist at Ohio State University in Columbus and the editor of the journal Language, says that the work is clever, however adds that "the idea that language change does not occur at a steady rate is nothing new; 'bursts' of change and periods of stasis have long been recognized".
The study is published in the journal Science.