The study examined low-coverage genetic data from human remains dating from 3,300 to 400 years ago across 33 Caribbean archaeological sites. DNA preservation varied substantially between and within sites, with the type of remains and their burial conditions having strong effects.

The researchers found that DNA decays about four times faster in the Caribbean than in temperate regions and about 14 times faster than in subpolar settings. They also found that visual inspection of remains, although imperfect, can help identify samples likely to retain usable DNA.