Mostly because... I have no idea why. I mean we've discovered something very close to spears being used by people since ... well forever in terms of modern history.
And hunting being very important to the needs of certain homo sapiens sapiens populations would very much agree with your assessment. One advantage that we hold over primates is our ability to throw. Combine that with making spears and our ancestors quickly becoming apex predators makes sense.
And hunting being very important to the needs of certain homo sapiens sapiens populations would very much agree with your assessment. One advantage that we hold over primates is our ability to throw. Combine that with making spears and our ancestors quickly becoming apex predators makes sense.