Approximately how many different gestures can human beings produce

Mario Pei, a communications expert, has estimated that humans can produce up to 700000 different physical signs, 250000 of them being estimated to be produced only by the face according to Birdwhistel.

The hands produce approximately 5000 distinct gestures according to M H Krout, whereas G W Hughes has cataloged 1000 different postures accompanied by specific gestures.