Ancient DNA and paleogenetics: risks and potentiality.

Paleopathology, the science that studies the diseases of the past, has always been addressed to the future in the use of new diagnostic methods. One of its relatively recent branches is paleogenetics, which is the study of genetic material from the past. Nuclear and mitochondrial DNA recovered from archaeological and paleontological specimens is called ancient DNA (aDNA), which can be extracted from a large variety of biological materials, of different origin, state of preservation and age, such as bones, teeth, coprolites, mummified tissues and hairs. There are many applications for ancient DNA research in the field of archaeology and paleopathology: population demography, genealogy, disease studies, archaeological reconstruction of plant vegetation, calibration of the molecular clock, phylogenetic relationship between different mammals and interpretation of the paleoclimate. However, the study of ancient genetic material is extremely difficult due to its poor quality and quantity, as well possible contamination with modern DNA. New advanced methods will allow extracting DNA from a greater variety of materials, and improvements in sequencing techniques will unveil data that are currently concealed. The aim of this paper is to provide initial insights into paleogenetics and ancient DNA study and to illustrate the limits, risks and potentiality of the research on the genetic material of ancient specimens, whose results have a strong impact on the present and future medicine.