[addingnumbers]

Yes, clearly they recognized the need to backpedal somewhat from their long string of intimations that these languages have savage and primal qualities.

Did you think that passage was a total non-sequitur? Are they cautioning you from believing something you would have no reason to believe? Or do you think they were aware they had unduly created that impression.

[pcrh]

On the contrary, they stress that using whistling to discover fundamentals of communication using sound does not imply that whistling was the original form of communication by sound.

[addingnumbers]

They could have achieved the same effect by never suggesting that whistling languages are primal or antiquated in the first place.

I suppose if I say "we shouldn't assume people who comment on HN posts are sad, lonely, and grumpy" I'm not being offensive or disrespectful. After all, I never said outright that anyone was any of those things. On the contrary, it actually says the exact opposite

It's a trick of language called insinuation.

[pcrh]

I think the point they are trying to make is that proto-language spoken by our ancestors would likely have had fewer components and reduced sophistication, as does whistling.

So identifying the minimum requirements for comprehensible, yet sophisticated, communication by sound would possibly shed light on what paleo-speech was like...