The Genomic Revolution and What Changed

The development of techniques for extracting, sequencing, and analyzing ancient DNA from archaeological specimens was one of the most consequential methodological advances in the history of human prehistory research, and its application to the earliest Americans has fundamentally transformed the field in ways that are still unfolding.

The basic challenge of ancient DNA analysis is preservation.

DNA degrades over time, damaged by chemical reactions with the surrounding environment, by microbial activity, and by the physical breakdown of the cellular structures that originally contained it.

The rate of degradation depends heavily on temperature, humidity, and the chemical composition of the burial environment: cold, dry, stable conditions preserve DNA much longer than warm, humid, chemically active environments.