Those questions also perpetually interest me. What is the burden of proof? Whose is it and how much? Burden of proof isn't a great term, I think, because hopefu

Those questions also perpetually interest me. What is the burden of proof? Whose is it and how much? Burden of proof isn't a great term, I think, because hopefully we're sort of working together, both interested in the truth. In this case, it seems you're overlooking that I provided an actual expert, an anthropologist, who provided an answer. IMHO, amatuers' (a group that includes me) attempts to interpret evidence may be interesting, but we are highly error-prone and our offerings pointless beside expert judgment. Also, you're not proving the negative (no reason to say 500 kya), just offering non-contradictory evidence that those tools appearing later also. Proving a negative, of course, is very difficult, but here we have an expert who apparently thinks otherwise. It would be hard to ignore the expert because another amatuer doesn't know of any evidence for it. To prove that negative, we'd need an expert saying so - e.g., 'the evidence says it began 350 kya at the earliest'. I think the answer is, we want comments to add value, be worth everyone's time to read. The standards of evidence will depend on what evidence is available and already posted - sometimes any shred of evidence helps; for topics drowning in misinformation, only high-quality evidence is worthwhile IMHO. Having said that, I'll have to look at mine and see if I met that standard!