Language Evolution
Language Log 2021-01-31
Today's SMBC starts this way:
The whole thing: 
The mouseover title: "Please share this comic to increase your hierarchy status."
The aftercomic: 
These Lecture Notes for ling001 have some discussion of various perspectives on this question.
An exchange between Tecumseh Fitch and Derek Bickerton on the topic:
"Musical protolanguage: Darwin's theory of language evolution revisited", 2/12/2009 "Bickerton on Fitch", 2/15/2009 "'Silence on the Savannah!' On Bickerton's Yodeling Australopithecines and Missing the Point of Musical Protolanguage", 2/20/2009
Some earlier background on Bickerton's own theory: "A new theory about the evolution of language", 6/11/2005.
And relevant to Darwin's idea — Julia Hyland Bruno, Erich D. Jarvis, Mark Liberman, and Ofer Tchernichovski, "Birdsong Learning and Culture: Analogies with Human Spoken Language", Annual Review of Linguistics 2021.