Ancient DNA investigations: A review on their significance in different research fields

In 1984, the extraction of DNA from dried muscle of the extinct quagga specie (Equus quagga) was a first in the analysis of ancient DNA (aDNA). Since, many studies have highlighted the feasibility of analyzing DNA from all type of ancient tissues including bones, hair, teeth and even coprolithes. Today, aDNA is widely investigated in several research fields. It is a useful tool in archeaozoology to elucidate the biology and the evolution of extinct species. In paleobotany, aDNA is used to reconstruct the paleoenvironments and to determine the time and place of the domestication of many varieties. It is also a powerful tool in forensic science to identify undetermined remains. In anthropological research aDNA provide important information to trace geographic distribution of human genetic variation and to reconstitute settlements history. However, its degradation and post-mortem chemical alteration make difficult its quantification and amplification. Moreover the study of aDNA is challenging due to the contamination by exogenous current DNA. Recently, the progress of molecular techniques and the use of sophisticated approaches greatly improved the ratio of endogenous DNA to contaminant DNA and allowed a better and more powerful aDNA investigation.