Powers of Babel. (cover story)

The article examines linguistic diversity, looking at research on why human beings speak many different languages. In a study in the journal "Science" Quentin Atkinson at the University of Auckland found that the serial founder effect, which is used to explain declines in genetic diversity away from Africa, also applies to the number of phonemes in languages, while Robert L. Munroe of Pitzer College found that languages in warm countries often used more vowels. In a study in the journal "PLoS One," Gary Lupyan at the University of Wisconsin-Madison found that insular languages which are spoken by few people are often more complex, while languages spoken by many people have simpler grammatical rules.