Languages are cruel, competitive creatures. Two different studies, from two different continents, looked at how languages have trouble playing well with others: One found that isolation allows for diversity because, as the other found, languages crush each other so predictably that physicists can actually model it.
A team of researchers from the University of Tokyo finally proved what people have long-suspected: that just as isolation allows for incredible biodiversity—think the Galapagos Islands—it also allows for linguistic diversity.
As the publication of the results in the Journal of Evolutionary Biology might indicate, this is one of those very cool, cross-discipline sorts of studies. The study's lead author is from the department of biological sciences and the co-author is from the cognitive and behavioral sciences department. I guess only a team like that would recognize there was something happening among the Japanese languages and the country's many islands.
Japan was the perfect place to test this hypothesis, since, as the researchers note: "Japonic languages are distributed across islands of different sizes that naturally allow them to be either separated or connected by geography, thereby forming two naturally comparable conditions." What's more, all of the languages share a recent common ancestor. "The time of their origin is reasonably well controlled and it is thus possible for us to interpret the influence of geographical barriers in a relatively straightforward manner."
And indeed, as the researchers measured the degree of beta diversity from basic vocabularies, the geographical proximity and isolation by surrounding ocean independently explained a significant proportion of lexical variation across the Japonic languages.
It's not the only similarity between languages and animals discovered by a cross-disciplinary team. Other researchers were able to model the pace at which a dominating language chokes out the competition.
There are a few different ways that a language goes extinct. According to UNESCO, "a language disappears when its speakers disappear or when they shift to speaking another language—most often, a larger language used by a more powerful group. Languages are threatened by external forces such as military, economic, religious, cultural or educational subjugation, or by internal forces such as a community's negative attitude towards its own language."
Either way, the shift seems to go from the indigenous tongue to the one perceived as more socially and economically advantageous, which can spell "death or doom of minority languages," according to a study in the Journal of the Royal Society. It's so predictable that the researchers, in this case both physicists, of all things, were able to model the pace at which one language swallows the other.
The researchers looked at the rise of English in Wales, as well as the rise of Spanish in Peru, and the decline of Scottish Gaelic in Sutherland, Scotland, and were able to use their model to pace the linguistic front, which in the case of the Welsh was about 0.3-0.6 km per year.
The authors allude to using the tools in order to preserve a language, but there's something retrograde-feeling about looking at the spread of languages without reference to the great linguistic threat—or possible savior—of our time: the internet.
It seems like in the near future all populations, whether isolated on an island or not, will be connected to the internet, which brings with it the advantage of knowing English, Chinese, and the world's other heavy hitters. Maybe the next cross-disciplinary linguistics study should be done by computer scientists.