This is Scientific American 60 Second Science.

I'm Christopher in D'Alata.

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Winter is high time for humidifiers because dry air can irritate your throat.

But a new study finds that arid conditions

might have influenced the development

of the varied languages that some people speak.

Extensive research on human physiology

suggests that really dry air makes it harder for us to use our vocal

chords very precisely.

Caleb Everett, an anthropological linguistics professor at the University of Miami. He and his colleagues recently

investigated that dry throat phenomenon in regards to complex tonal languages like

Cantonese. Where various combinations of rising and falling tones can actually change the meaning of a word as opposed to non-tonal languages like English or Italian.

In the non-tonals, the fundamental meaning is the same.

Whether I say, word, or word.

By mapping the distribution of more than 3,700 tonal and non-tonal languages, Everett and his colleagues

found that tonal languages tend to cluster in warm humid areas, and they're ten times less prevalent in dry sub-freezing climbs

like Siberia compared with non-tonal languages. The studies in the proceedings of

the National Academy of Sciences. Of course it's physically possible to speak a tonal language in a cold place.

Obviously speakers of Cantonese for instance can communicate in Siberia and in other dry places.

The big picture, Everett says, is that language evolves in relation to where it's spoken.

Language does not evolve in a vacuum.

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