In response to some reader requests for clarification:
At the top a Clovis spearpoint from Nevada – not visible here but both sides of the point have been worked. Note the characteristic fluting at the right. The flute gets forced into the split end of the shaft. Perhaps it was glued or tied. Load up the spear on a favorite atlatl, and any BIG game nearby had better vacate the locale.
At the bottom a microblade assemblage. A knapper would strike off multiple sharp small blades (five of them used above) probably from a common core. Then something like a bone or antler or perhaps even a sturdy branch would have a groove cut into it. The microblades are forced in, and one has a knife or spearpoint.
Currently, the issue of Paleolithic weapons technology needs more data. It was very inconsiderate of early hominids not to invent the Internet and blog about their lives. Or at least invent writing and pound out petroglyphs. At present, the evidence suggests that microblade technologies were used as early as 30,000 years ago in southern Siberia, northern China, or the Hokkaido-Sakhalin area. It has been conjectured that Clovis technologies originated with the Solutrean culture which was prevalent in southern France and northern Spain 17,000 to 22,000 years ago. Clovis points in North America generally date to between 13,200 to 13,700 years ago. It is difficult to imagine a rapid changeover from microblades to Clovis so it would be just swell if someone found some sort of intermediate technology of more or less the right age in Alaska or Washington state.
An important practical question for us is are we using the right tools when trying to help people with special needs. From the perspective of the analysis of modern (21st century) immigration it is obvious (to us) that, like lithic technology, a lot more detailed data is needed. In the last twenty thousand years ago Beringia has sunk, sea levels have risen and fossils remain elusive. For 21st century immigration across the US-Mexico border it is very challenging to even guess how many illegal immigrants (to the nearest million!), when they crossed, where they crossed, what their fates were and what economic impact they had.
Here’s a link to some additional material on 21st century immigration across the US-Mexico border US Immigration