Wear on 500 Tennessee Valley spear points suggests Ice Age hunters learned where to find stone

The study relies on what the valley has plenty of. "There aren't that many archaeological sites for these people that we can dig, but what we have instead are lots and lots of points that people have found in this region," Miller said ^[10]. Tune described the team as trying "to see the rest of their behaviors through the lens of these spear points because that's what we have" ^[13].

Resharpening tells you something because the object was cheap. "Spear points were designed to be disposable objects, and that makes what the Clovis were doing interesting," Tune said ^[2]. Reworking a throwaway tool costs time and stone, so a hunter who does it has a reason. The authors tie that reason to how much a person could carry. "When you think about a people who are moving around a lot, understand that they didn't have any pack animals," Miller said ^[11]. He added: "You really don't want to be carrying around a bag of rocks, and so you're going to be judicious about balancing what you need versus what you can carry" ^[12].

On that account, a group unsure where the next chert deposit lies has reason to stretch the stone it already carries. A group that knows can drop a working point and make another. The researchers put the Cumberland discards in that second case, as evidence that the later hunters had learned where to resupply and were more comfortable in their surroundings ^[9]. I think the design suits the question. It compares one kind of object, in one region, across two populations, and the difference the authors care about is how long people had known the place [c2, c7].

The thing this doesn't tell you is how large the difference is. The phys.org account does not report how the roughly 500 points divide between Clovis and Cumberland, or what share of each shows resharpening ^[4]. Without those figures, "more likely" could mean a wide gap or a narrow one ^[1]. The inference is also correlational. Period tracks wear, and landscape knowledge is the explanation the authors offer to connect the two. The account itself says only that the Clovis resharpening possibly signals concern about managing resources ^[1]. Anything else that changed between the two groups over several hundred years would also leave marks on the same stone ^[7].

Tune takes the idea further than the points can. "There really is no difference between Ice Age hunter-gatherers and the people sending missions and rovers to Mars," he said ^[14]. The evidence under that sentence is resharpening and discard on stone points from one river valley ^[4].