I'm writing a biological anthropology research paper on

I don't know anything about this but I remember an anecdote Herodotus' Histories where Pharaoh Psamtik I carried out an experiment where he sent a newborn to be raised by a deaf-mute to see if he would develop language on his own, and the kid would make a sound when he was hungry that resembled the Phrygian word for 'bread,' which led Psamtik to conclude that the Phrygian language was the original proto-language. Maybe you can put that in the introduction or background sections to seem cultured and knowledgeable.

>>8499051
>how language or linguistics developed/evolved among early humans.

No-one knows.

>>8499051
>I know proto-language developed out of Neandertals need to communicate amongst each other -- hunting, foraging, toolmaking, etc. It was mainly symbolism and rare vocalization.

You don't know this, no-one knows this. Language probably predates our subspecies, like the mastery of fire does.

>early humans
If you mean early homo sapiens then it was already there, linguistic capability is finely ingrained in our dna.
If you mean protohumans there are theories about it but nothing certain.

Look into anything related to the hyoid bone and it's presence (or absence) in the fossil record. I know that's got more of a physanth lean to it, but that little bone is vital for speech as we know it.