What is DNA?
DNA stands for deoxyribonucleic acid. It is the hereditary material in humans and almost all other organisms and is sometimes referred to as a genetic blueprint. This is because it contains the instructions that govern the development of an organism. Nearly every cell in a person’s body has the same DNA. Most DNA is located in the cell nucleus where it is called nuclear DNA. An important property of DNA is that it can replicate or make copies of itself.
DNA has four major functions. Firstly, it contains the blueprint for manufacturing proteins and enzymes. DNA also plays a role in regulating when the proteins and enzymes are made and when they are not made. Further, it carries information about when cells divide. Finally, DNA transmits information from parental organisms to their offspring.
DNA was first introduced as evidence in the United States court system in 1987. The biological material used to determine a DNA profile in forensics include blood, semen, saliva, urine, faeces, hair, teeth, bone, tissue and cells.
Forensic evidence is evidence obtained by use of scientific methods and relied upon in a court of law to prove a fact. Anything can be forensic evidence and forensic evidence can be found anywhere. Forensic evidence may be used for identification. This involves classification of items. Here, items are assigned to categories containing like items. Further, objects are identified by comparing their class characteristics with those of known standards.
Forensic evidence can also be used for individualisation. This refers to the demonstration that a particular sample is unique even among members of the same class. It is also a demonstration that a questioned piece of physical evidence and a similar known sample have a common origin. This means that in addition to class characteristics, you look for individual characteristics e.g. individualisation of persons through fingerprints.
Further, forensic evidence can be used for reconstruction. This is the process of putting the ‘pieces’ together in a case or situation with the objective of reaching an understanding of the sequence of past events based on a record of physical evidence.
Main Uses of DNA Forensics
Forensic science is the application of natural science to matters of law. In practice, it draws upon principles and methods of traditional sciences such as physics, chemistry, and biology. It is concerned only with natural phenomena i.e. things and processes that are subject to observation, measurement and experimentation. Wildlife forensic science is science applied to legal questions involving wildlife crimes.
Forensic science contributes to solving wildlife crimes through investigative activities like determining the cause of wildlife death, identifying suspects, finding missing wildlife and profiling wildlife. In its simplest form, wildlife forensics seeks to link the crime scene, the suspect, and the victim in a way that is admissible in court and can be used to prosecute and convict those involved in wildlife crime.
Forensic DNA gives the criminal justice field a powerful tool for convicting the guilty and exonerating the innocent. Scientists can use DNA to generate the profile of an individual or animal using samples from body tissues and products. The continued development and integration of wildlife DNA forensics will be critical for successful management of the many significant social and conservation issues related to the illegal wildlife trade and wildlife law enforcement.