John wrote:
>> I don't understand why independent innovation should be so unlikely? Surely
>> there's plenty of cases where unrelated languages have acquired more-or-less
>> exotic sounds independently?

>The mystery of clicks is that nobody can figure out how they could have resulted
>from a reasonable sound-change in some other language.

There is one example of clicks outside Africa: Damin.
But OTOH, Damin was deliberately made exotic ...

BTW, I take the article with a grain of salt.