"Contemorary Science" (I have to guess at what you mean by that) has a great reputation amongst educated people. What makes you think it has a bad reputation? I don't think the Global Warming pimps have undone the mapping of the Genome.
You state an estimate range going back perhaps as much as 500,000 years. But not 600,000? Not 700,000? No, no, but 500,000 is a definite possibility (more recent is more likely, of course, but the range of informed estimates goes back as much as 500,000 years).
Scientific estimates of what happened a long, long time ago tend to point to magnitude. 1/4 million, 1/4 million, it ain't billions.
Human language--speech--developed perhaps 250,000 years ago (informed estimates range from 100,000 to 500,000 years ago. Before speech involving words and primitive grammar, there was posture, arm language, facial expressions, as means of communication.
All I'm seeking is evidence of "posture, arm language, facial expressions, as means of communication" dating back 500,000 years.
Do you have any evidence? Or it it all supposition? And why can't the supposition go back 600,000 years? Why 500,000? There must be a reason -- right?
Please understand: I'm not saying there couldn't have been gestures. I'm not denying that animals engage in forms of communication. I'm merely pointing out that some scientists like to pretend to be rigorous and pretend that everything they believe is based on solid evidence. And it sure sounds like they know what they're talking about, because they've got numbers and estimated dates to back them up.
But I'm just asking: What exactly makes us think that gestures existed 500,000 years ago -- but not 600,000? A hypothesis has a role in science, certainly. But sometimes it seems like conjecture is valued about as highly as evidence.