Quite so - Adam as H. erectus is someone else’s idea!
Homo erectus certainly did have the anatomical requirements for speech as well as hearing tuned to that speech.
The anatomical differences between the speech and hearing of Erectus and Sapiens show a gradual evolution of both the speech and hearing apparatus as speech, language, hearing, culture evolved.
This is covered in the book extensively. What I found fascinating is all the other nuances of language like facial expressions, gestures, and hand motions that evolved along with the speech and hearing. Language has a two million history of advancement. Language is tied to culture and evolves along with it.
Maybe it’s another one of those one sided pop science books… human language is understood to have emerged between 50000 to 100000 years ago… I will share an article that gives the details . One major factor is the presence of fully developed vocal cords.
Having said that. I am sure the homo erectus had some sort of communication… perhaps involving a mix of sound and gesturing… like modern primates do… or maybe more advanced.
However I don’t think what they had was the first language as we understand language.
I don’t know how you get from artifacts to language, but never mind. There’s coalescence in languages as well as genes. The common ancestor of extant languages is almost certainly much more recent than the common ancestor of all languages, just as mt-Eve is not the first hominid female. I would make the wild-ass guess that the coalescent of all extant languages would be around 50K years ago, around the time of the dispersal of modern humans from Africa. But it’s hard to trace any language relationships more than a quarter of that distance.
I look forward to a better understanding of this topic over the next decade or so. As with most evolutionary transitions, there seem to be two schools of thought on the evolution of language: a gradualist and saltationist school. I’m eagerly anticipating what research yields.