The Use of Dna in Studying Mummies

Outline the use and limitations of DNA in the study of ancient remains. Give different sources of DNA sampling. Outline the types of information that can be retrieved for each different sources of DNA

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Ancient DNA (aDNA) is an invaluable source of information to draw upon when studying ancient human remains due to the depth and variety of information that can be garnered from it. However, depending upon the quality and type of DNA extracted there are limitations to the uses of aDNA. These limits come from the inevitable degradation of the aDNA as well as the high probability of contamination. These limits are entirely determined by the origin of the aDNA and its state of preservation, both historical and modern. Due to the presence of DNA in just about all living cells there are numerous possible sources of aDNA each with its own advantages and disadvantages.

The major store of DNA within the body is the soft tissue and organs, comprising the vast majority of the cells of an organism. Almost as soon as the body dies a rapid process of decomposition begins. This process involves the autolysis of the body’s soft tissues and subsequent damage to the DNA via catabolic enzymes such as lysosomal nucleases, accompanied by putrefaction. This is caused by the metabolic processes of decomposing bacteria and saprobic fungi. Unless these processes have somehow been slowed or prevented very rapidly after death, the likelihood of retrieving DNA from the soft tissues of the body is very remote. Due to this rapid decomposition it has to be understood that any aDNA that is extracted and sequenced from organic remains will most likely be a mixture of the endogenous DNA sequence and contaminant DNA sequences [1]. Also any DNA present is likely to be damaged in numerous ways dependent upon the preservation conditions it has been subjected to until the present day.

The vast majority of archaeological remains that have yielded usable aDNA have been the...