This argument — developed most prominently by researchers including the late Walter Neves in South America and others working on North American material — suggested to some that the earliest Americans might not be the direct ancestors of historical and contemporary Native American peoples.

This morphological debate was scientifically complex and methodologically contested, and it intersected uncomfortably with another hypothesis that had attracted attention in certain scientific circles.

The Solutrean hypothesis, developed and advocated primarily by Dennis Bradley and Bruce Stanford of the Smithsonian Institution, proposed that the technology underlying Clovis points had not developed from Asian stone tool traditions but rather from the Solutrean tool tradition of Ice Age Europe — specifically the Iberian Peninsula and southwestern France, where similar-looking bifacially thinned stone points had been made approximately 21,000 to 17,000 years ago.

Under this hypothesis, Ice Age European people had followed the productive margins of the North Atlantic pack ice from Europe to North America, reaching the Americas from the east rather than from the west.