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An essay on the biological role of DNA
Forensic science and the role it plays in solving crimes
Role of forensic science
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The structure of DNA was discovered in 1953 and revealed to the world by James Watson and Francis Crick.1 Since then, there has been a whirlwind of activity and discovery in the fields associated with DNA. We have found that DNA is not only a set of instructions for the body, but that it also contains a lot of information about the individual who “owns” the DNA. As it is rapidly becoming cheaper and easier to process DNA, it is becoming more difficult to make sure that there is adequate legislature to protect members of society.
Most genes are actually shared by all of humanity. In fact, 98% of human DNA is also shared with chimpanzees.2 However, some repeating units are unique and they can tell us much information about the individual the DNA came from. Many things can currently be determined from DNA. These include physical characteristics like gender, hair colour, and eye colour, and non-physical characteristics like the chance that individual has of developing, or passing on to children, diseases such as breast cancer, Huntington’s disease and cystic fibrosis.3 Technology has improved so much that eye colour group (light, dark or hazel) can be predicted with 97% accuracy.4
DNA profiling is a technique in which a sample of the unique part of DNA is taken, cut using restriction enzymes and separated by size using gel electrophoresis. Gel electrophoresis is where an electric current moves DNA strands through agarose gel towards the positive electrode. This makes a “DNA fingerprint”. (See Figure 1.) DNA profiling has a number of uses including paternity and kinship tests as well as in forensic science to solve crimes. In Victoria, the law allows the collection of DNA samples of convicted criminals and suspects. These DNA profil...
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...hat are unique to an individual. As technology is developing so fast, it is important that people in authority, for example judges and politicians, make sure that there are laws in place that protect the rights and safety of citizens in terms of how their DNA information is used and stored. They also need to make sure that they consider DNA as a piece of evidence that is usually very reliable but also has its limitations and exceptions and can never be 100 percent accurate. The general public can now get their DNA fingerprints made as a piece of artwork. As this is so easy and fairly inexpensive, people need to be aware of any implications this could have. For the most part, it would be harmless and an unusual item to own, however, people should make informed decisions when it comes to their personal details, including their DNA, now and even more so in the future.
In certain situations, it is necessary to identify DNA retreived from a sample. When there is a
Deoxyribonucleic acid (DNA) is an acclaimed extraordinary discovery that has contributed great benefits in several fields throughout the world. DNA evidence is accounted for in the majority of cases presented in the criminal justice system. It is known as our very own unique genetic fingerprint; “a chromosome molecule which carries genetic coding unique to each person with the only exception of identical twins (that is why it is also called 'DNA fingerprinting ')” (Duhaime, n.d.). DNA is found in the nuclei of cells of nearly all living things.
The analysis of the samples should be used only to confirm or negate match between the sample taken from the crime scene fgand the sample taken from the suspect. That is, it should sdfremain as an identifgication tool only. There should be no further analysis of the DNA to suggest psychological characteristics that would make the suspect more likely to have cdfommitted the crime. This rule should apply also to samples taken from convicted dfdoffenders for a data vor dagta bank.
. DNA can be left or collected from the hair, saliva, blood, mucus, semen, urine, fecal matter, and even the bones. DNA analysis has been the most recent technique employed by the forensic science community to identify a suspect or victim since the use of fingerprinting. Moreover, since the introduction of this new technique, there has been a large number of individuals released or convicted of crimes based on DNA left at the crime scene. DNA is the abbreviation for deoxyribonucleic acid.
DNA is the blueprint of life. It stores our genetic information which is what is in charge of how our physical appearance will look like. 99.9% of human DNA is the same in every person yet the remaining .1% is what distinguishes each person (Noble Prize). This small percentage is enough to make each person different and it makes identifying people a lot easier when its necessary. DNA not only serves to test relationships between people it also helps in criminal cases. DNA testing in criminal cases has not been around for many years if fact it was not until the early 1990s when the use of DNA testing for criminal cases was approved and made available. By comparing the DNA of a suspect and that found in the crime scene a person can either be convicted of a crime or they can be exonerated. This method of testing gained more publicity in the 1984 case of Kirk Noble Bloodsworth a man who had been convicted of the rape and first degree murder of a nine year old girl in Maryland. His case was a milestone in the criminal justice system since it involved the use of new technology and it also raised the question of how many people had been wrongly incarcerated for a crime they did not commit.
Nowadays, DNA is a crucial component of a crime scene investigation, used to both to identify perpetrators from crime scenes and to determine a suspect’s guilt or innocence (Butler, 2005). The method of constructing a distinctive “fingerprint” from an individual’s DNA was first described by Alec Jeffreys in 1985. He discovered regions of repetitions of nucleotides inherent in DNA strands that differed from person to person (now known as variable number of tandem repeats, or VNTRs), and developed a technique to adjust the length variation into a definitive identity marker (Butler, 2005). Since then, DNA fingerprinting has been refined to be an indispensible source of evidence, expanded into multiple methods befitting different types of DNA samples. One of the more controversial practices of DNA forensics is familial DNA searching, which takes partial, rather than exact, matches between crime scene DNA and DNA stored in a public database as possible leads for further examination and information about the suspect. Using familial DNA searching for investigative purposes is a reliable and advantageous method to convict criminals.
The more we know about genetics and the building blocks of life the closer we get to being capable of cloning a human. The study of chromosomes and DNA strains has been going on for years. In 1990, the Unites States Government founded the Human Genome Project (HGP). This program was to research and study the estimated 80,000 human genes and determine the sequences of 3 billion DNA molecules. Knowing and being able to examine each sequence could change how humans respond to diseases, viruses, and toxins common to everyday life. With the technology of today the HGP expects to have a blueprint of all human DNA sequences by the spring of 2000. This accomplishment, even though not cloning, presents other new issues for individuals and society. For this reason the Ethical, Legal, and Social Implications (ELSI) was brought in to identify and address these issues. They operate to secure the individuals rights to those who contribute DNA samples for studies. The ELSI, being the biggest bioethics program, has to decide on important factors when an individual’s personal DNA is calculated. Such factors would include; who would have access to the information, who controls and protects the information and when to use it? Along with these concerns, the ESLI tries to prepare for the estimated impacts that genetic advances could be responsible for in the near future. The availability of such information is becoming to broad and one needs to be concerned where society is going with it.
One of society’s problems is that the wrong people are convicted of a crime they did not commit. None have more dire consequences on those than who are wrongly convicted of rape and murder. The punishment for these crimes are as harsh as possible to deter the crimes and when wrongly convicted, the wrong person gets punished while the true perpetrator gets away. In order to increase the chance of convicting the true perpetrator of the crime, the tools to find and convict criminals had to be refined. And it was refined due to extensive research into DNA. This research was done by Alec Jeffreys and Vicky Wilson, the research’s technician, and it found that in the massive amount of junk codes, there exists many repetitious codes that have copied so many times that it varies from person to person. (Ridley 132) This means that people can be identified with only their DNA from their hair, fluids, skin, etc. This discovery has led to convictions of rapists and murderers such as the Pickford case that Ridley wrote about. It has also led to the sentences of many wrongly convicted people to be retracted and this had led to the release of about 200 people known as the DNA 200. (Phelan) Now, most of the world keeps criminals’ genotype information in order to identify repeat offenders. In the United States, every state requires that every convicted
"The discovery of the structure by Crick and Watson, with all its biological implications, has been one of the major scientific events of this century." (Bragg, The Double Helix, p1) In the story of The Double Helix, James Watson tells of the road that led to the discovery of life's basic building block-DNA. This autobiography gives insight into science and the workings within a professional research laboratory that few members of society will ever be able to experience. It also gives the reader an idea of the reality of life for one scientist and how he struggled with the problem of DNA. However, the author's style is marked by his lack of objectivity and inclusion of many biased opinions and personal prejudices.
The genetic technology revolution has proved to be both a blessing and a blight. The Human Genome Project is aimed at mapping and sequencing the entire human genome. DNA chips are loaded with information about human genes. The chip reveals specific information about the individuals’ health and genetic makeup (Richmond & Germov 2009).The technology has been described as a milestone by many in that it facilitates research, screening, and treatment of genetic conditions. However, there have been fears that the technology permits a reduction in privacy when the information is disclosed. Many argue that genetic information can also be used unfairly to discriminate against or stigmatize individuals (Willis 2009).
Once a crime has been committed the most important item to recover is any type of evidence left at the scene. If the suspect left any Deoxyribonucleic acid (DNA) at the crime scene, he could then be linked to the crime and eventually charged. A suspect’s DNA can be recovered if the suspect leaves a sample of his or her DNA at the crime scene. However, this method was not always used to track down a suspect. Not too long ago, detectives used to use bite marks, blood stain detection, blood grouping as the primary tool to identify a suspect. DNA can be left or collected from the hair, saliva, blood, mucus, semen, urine, fecal matter, and even the bones. DNA analysis has been the most recent technique employed by the forensic science community to identify a suspect or victim since the use of fingerprinting. Moreover, since the introduction of this new technique it has been a la...
Before the 1980s, courts relied on testimony and eyewitness accounts as a main source of evidence. Notoriously unreliable, these techniques have since faded away to the stunning reliability of DNA forensics. In 1984, British geneticist Alec Jeffreys of the University of Leicester discovered an interesting new marker in the human genome. Most DNA information is the same in every human, but the junk code between genes is unique to every person. Junk DNA used for investigative purposes can be found in blood, saliva, perspiration, sexual fluid, skin tissue, bone marrow, dental pulp, and hair follicles (Butler, 2011). By analyzing this junk code, Jeffreys found certain sequences of 10 to 100 base pairs repeated multiple times. These tandem repeats are also the same for all people, but the number of repetitions is highly variable. Before this discovery, a drop of blood at a crime scene could only reveal a person’s blood type, plus a few proteins unique to certain people. Now DNA forensics can expose a person’s gender, race, susceptibility to diseases, and even propensity for high aggression or drug abuse (Butler, 2011). More importantly, the certainty of DNA evidence is extremely powerful in court. Astounded at this technology’s almost perfect accuracy, the FBI changed the name of its Serology Unit to the DNA Analysis Unit in 1988 when they began accepting requests for DNA comparisons (Using DNA to Solve Crimes, 2014).
“The rapid implementation and continuing expansion of forensic DNA databases around the world has been supported by claims about their effectiveness in criminal investigations and challenged by assertions of the resulting intrusiveness into individual privacy” (p545).
Simply put, DNA contains the instructions needed for an organism to develop, survive, and reproduce. The discovery and use of DNA has seen many changes and made great progress over many years. James Watson was a pioneer molecular biologist who is credited, along with Francis Crick and Maurice Wilkins, with discovering the double helix structure of the DNA molecule. The three won the Nobel Prize in Medicine in 1962 for their work (Bagley, 2013). Scientists use the term “double helix” to describe DNA’s winding, two-stranded chemical structure.
The Use of Recombinant DNA Technology Recombinant DNA technology is the technology of preparing recombinant DNA in vitro by cutting up DNA molecules and splicing together fragments from more than one organism.(1) This is the process of using recombinant DNA technology to enable the rapid production of human protein from a single gene of insulin. Firstly the single gene required must be isolated. This can be done three ways: Either by working backwards from the protein- Finding the amino acid sequence for the protein needed, the order of bases can be established using known genetic code. New DNA can be made from this sequence of bases resulting in artificial gene made from complementary DNA.