The Solutrean Theory was based on marked similarities in form and knapping technique in very old spear heads found in New England and Virginia. Geneticists could not, however, find a meaningful connection between haploid groups in modern Native Americans and Anatolians (descendants of Solutreans).
If a small band or even a long term, gradual migration of Solutreans had walked and kayak-ed across the last Ice Age's pack ice via Iceland and Greenland to North America, then a small remnant of the genes should have shown up in the gene pool here. The theory was intriguing, but it turned out that the spear head similarities were a good example of "form follows function".
I came up with my own version of the Solutrean hypothesis: that a single Solutrean kayak made it to the Chesapeake Bay area, and wintered with a friendly tribe they encountered. At one point, some curious local saw one of the Solutreans making spearheads, and the Solutrean demonstrated his technique.
In spring, they went home (or died trying). Or maybe not. It's fairly plausible that the Solutrean genes, if they came from a literal handful of migrants, disappeared into the background, especially when you had the Younger Dryas period that depopulated most of the continental US.
Regardless, the idea that the Solutreans were anything more than a miniscule contribution to the peopling of the Americas is ludicrous.
