Ancient DNA research — the study of genetic material preserved in archaeological or paleontological specimens — has undergone a revolution since the first successful extractions of ancient DNA in the 1980s.

Early work was limited to short sequences of mitochondrial DNA, the small circular genome found in cellular mitochondria that is inherited only through the maternal line and that is present in many copies per cell, making it easier to recover than the nuclear genome.

The development of next-generation sequencing technology in the 2000s and 2010s transformed ancient DNA research.

Next-generation sequencing reads enormous numbers of short DNA sequences simultaneously, making it possible to reconstruct genomes from the highly fragmented and damaged DNA that survives in ancient specimens.

Combined with increasingly sophisticated methods for extracting ancient DNA from bone and tooth material, and for authenticating genuine ancient sequences against modern contamination, these advances opened the door to the study of complete or near-complete genomes from ancient human individuals.