>> All of the anthropologists studies that I have read agree  that it
started
>> near the beginning of the agricultural revolution

> Wonder what they used for evidence? Nomadic herdsmen don't make a lot of
> marks, other than many hoofprints.

Aye, there's the rub. The article I referred to in my last post said
exactly that. Ag leaves loads of evidence, herding very little (herders
are, after all, migratory by nature). Nevertheless, it is generally
accepted that herding started before agriculture. Exactly how long before
is still unknown.