Ancient DNA research is carried out by retrieving DNA sequences from museum specimens, archaeological finds, fossilized and mummified remains, and ancient microorganisms embedded in ice, rock, or amber. Only a miniscule amount of the original matter is present in these sources. For years, researchers struggled with their tiny and often degraded samples of ancient DNA, and the fruits of their labor were often equivocal.

Salem Press Encyclopedia of Health, 2022. 5p.