Clovis is based on artifacts, it’s not an ethnic, genetic or linguistic group. We can’t say for sure that there were two different, contemporary groups of “Clovis People” and “Paisley Cave People” based on the current evidence. There’s genetic evidence now that with strong likelihood can be connected to the Paisley Cave artifacts, but none to Clovis. Clovis is all about archeological material.

It might be an off-shoot of the Paisley Cave cultural tradition. Perhaps they represent a totally different migration wave, perhaps the rather crazy Atlantic crossing theory is correct – who knows? But differences in making of artifacts don’t have to mean that the population or cultural landscape of North America in circa 13 000 years ago would have been truly heterogenous. All we know is that in one place of the Pacific coast people were making some of their artifacts differently than was being done by the makers of the Clovis.

Based on what we now know, and considering that the attempts at connecting Clovis to Old World traditions are speculative at best and that the new artifacts from Paisley Cave do show strong connections to Siberian artifacts, I would think that the most likely explanation at this point would be that the Clovis just represents a succesful innovation by one local group of the Paisley Cave people, an innovation which then spread rapidly.