Mitochondrial DNA

Mitochondrial DNA is found in the mitochondria of all living organisms. While DNA is present inside of the nucleus of all cells in the body, DNA found in the mitochondria are found in more abundant quantities compared to the amounts found in other cells, meaning that fewer samples are required in order to conduct a successful archaeological analysis of an individual’s DNA. Forensic scientists use a variety of types of DNA analysis when examining human remains found in archaeological excavations, including mitochondrial DNA, more commonly referred to as mtDNA.

Mitochondrial DNA is extracted from the cellular organelle known as a mitochondrion. A mitochondrion is a small cell structure located in the cytoplasm of eukaryotic cells, the cells found in living organisms with complex cell structures, such as humans, animals, plants and fungi. Mitochondria transform energy into energy-harvesting molecules known as adenosine triphosphate (ATP), which provide the body’s cells with energy.

mtDNA testing is advantageous in the analysis of archaeological findings because mtDNA can be extracted from samples that do not contain nucleated cellular material, such as hair, bones and teeth. Therefore, DNA testing can be collected on soft connective tissue, which is generally found in smaller amounts and which is not as well preserved as hair, bones and teeth. This gives mtDNA great value when uncovering human remains of individuals who lived during ancient times.

Another important feature of mtDNA is that it can trace the genealogy of an individual through his or her mother. All mothers have the same mitochondrial DNA as their offspring, because the mitochondria of each new embryo originate from the mother’s egg cell. On the other hand, an individual’s father contributes only nuclear DNA, which provides a less clear genetic profile. Because of the matrilineal nature of mtDNA, mtDNA analysis enables archaeologists and forensic scientists to establish the nature of the relationship between the individual and possible maternal relations through the creation of a direct genetic line, giving this type of DNA testing significant value in the field of archaeology.

In addition, compared with nuclear DNA, sections of mtDNA do not recombine, meaning that mtDNA provides a clearer genetic profile of the individual. Because mtDNA is so effective, it remains the leading type of DNA analysis used in the field of archaeology today. It is an essential tool in identifying human remains from ancient times, and has been especially crucial in identifying bones located in tombs and ossuaries in and around the city of Jerusalem.