A recent Aeon Essay asks If language began in the hands, why did it ever leave? but do anthropologists really fixate on deciding which kind of communication came first while ignoring the obviously most likely alternative?
Surely the utility of vocalization for attracting attention and gesture for directing it have always been linked in the evolving communication strategies of every organism with the capacity for making sounds.
And when it comes to humans the pressure to advance both together has always been strong. Whining and begging are more effective together than either alone, and yelling “tiger” and pointing will save more lives than either a purely vocal or purely gestural approach. So it is not surprising that evolution has provided a deep link between the two modes. But it is as important to keep eyes ahead while running in a pack to chase down prey as it is to avoid texting while driving. So I am not surprised that strategic instructions such as “you go left while I go right” came to be delivered vocally rather than by hand signal. (And the article’s reference to silence during hunting is bizarre. Although an individual might have needed silence to surprise a frog or grouse, that type of hunting is usually solitary, and our group hunting style of chasing to exhaustion might well have been enhanced by making a lot of noise.)