This chapter discusses the extraction, characterization, molecular cloning, and enzymatic amplification of ancient DNA from various archaeological and museum specimens. The author, Svante Pääbo, examines the chemical and enzymatic properties of DNA extracted from dry remains of soft tissues ranging from 4 to 13,000 years old, representing four species, including two extant animals. The DNA obtained is typically of low average molecular size and highly damaged by oxidative processes, leading to modifications in pyrimidines and sugar residues, as well as baseless sites and intermolecular cross-links. These modifications make molecular cloning difficult but allow for the use of the polymerase chain reaction (PCR) to amplify and study short mitochondrial DNA sequences, which are of significant anthropological and evolutionary importance. The PCR method opens up the possibility of performing diachronic studies of molecular evolutionary genetics using museum specimens and archaeological finds. The chapter details the materials and methods used, including DNA extraction, molecular cloning, and enzymatic amplification, and presents results on the nature of DNA damage and the success of PCR amplification. The discussion highlights the challenges and potential of using ancient DNA for research in historic, evolutionary, and taxonomic contexts.This chapter discusses the extraction, characterization, molecular cloning, and enzymatic amplification of ancient DNA from various archaeological and museum specimens. The author, Svante Pääbo, examines the chemical and enzymatic properties of DNA extracted from dry remains of soft tissues ranging from 4 to 13,000 years old, representing four species, including two extant animals. The DNA obtained is typically of low average molecular size and highly damaged by oxidative processes, leading to modifications in pyrimidines and sugar residues, as well as baseless sites and intermolecular cross-links. These modifications make molecular cloning difficult but allow for the use of the polymerase chain reaction (PCR) to amplify and study short mitochondrial DNA sequences, which are of significant anthropological and evolutionary importance. The PCR method opens up the possibility of performing diachronic studies of molecular evolutionary genetics using museum specimens and archaeological finds. The chapter details the materials and methods used, including DNA extraction, molecular cloning, and enzymatic amplification, and presents results on the nature of DNA damage and the success of PCR amplification. The discussion highlights the challenges and potential of using ancient DNA for research in historic, evolutionary, and taxonomic contexts.