Chapter 11, a very interesting contribution to the book, deals specifically with click languages
and what they can or cannot tell us about the origins of language, proving that the use of clicks in paralinguistic utterances are no evidence of their linguistic antiquity.
Genetic comparison of two such tribes suggests that the unusual click languages, known as Khoisan languages, could resemble the ancestral tongue of all humankind.
For more than a century, linguists have debated the origins of these click languages, notes Alec Knight of Stanford University.
Other passengers came over, and soon I had an audience of almost a hundred -- a British missionary couple, a Hottentot family, Ovango men, Xhosa and !Kung with their melodious click languages
, and a smattering of Dutch and German engineers.