The field’s expansion through the 1990s brought both extraordinary opportunities and serious challenges.

The opportunities were clear: for the first time, researchers could potentially address questions of ancestry, population relationships, and genetic diversity in ancient populations using direct biological evidence rather than inference from skeletal morphology or archaeological association.

Questions that had been debated for decades — including questions about the origins and relationships of early American populations — could in principle be addressed using DNA sequences recovered from ancient individuals.

The challenges were equally serious.