Paleoindian demography and the extraterrestrial impact hypothesis

Buchanan et al. 2008: no demographic crash in the radiocarbon record

what the source states

Analysis of ~1,500 archaeological radiocarbon dates from across North America found no evidence of the human population decline at 12.9 ka predicted by the extraterrestrial-impact hypothesis; date frequencies show continuity through the boundary.

what we infer

A direct test of a distinctive prediction, published within a year of the hypothesis — and negative. Radiocarbon-frequency demography is an imperfect proxy, but the predicted signal was a continent-wide catastrophe, which is exactly the size of signal the method should see.

limitations

• Radiocarbon date frequencies conflate population size with site preservation and research intensity.