[Physicist]

The key word being "repeatedly," meaning the same favored rock gets used.

I could be wrong, but I believe the threshold for "repeatedly" is only a few whacks in one spot, enough to distinguish it from the natural bumping and grinding of stones. A couple of nuts should do it.

[Sabertooth]

I could be wrong, but I believe the threshold for "repeatedly" is only a few whacks in one spot, enough to distinguish it from the natural bumping and grinding of stones. A couple of nuts should do it.

I don't know either, but let's assume this is the case.

First, I still believe the earliest stone tools would be used once and disposed. Once you got to the point where a particular stone was used repetedly, that would suggest some way to keep track of it, probably at least a semi-permanent residence.

Such a clan of apes would by definition be isolated to a degree from others... who knows for how long? Toolmaking could have developed for a while before being learned by others of the species.

So I don't think it's a given that we've discovered the earliest stone tools, or even any that are necessarily close to the earliest.

So, any archaeologists lurking out there, start sifting the pebbles!