Minimal scientific training for judges, jurors and lawyers, and attention to correct execution, will bring in the near future the possibility of identification without instigators. The genetic cluster will revolutionize the legal system and strengthen society's ability to protect itself
For several years, the courts and police forces around the world have been perfecting their ability to identify people with the help of the wonders of modern molecular genetics. This is a genetic "fingerprint" or "clusteron", based on the analysis of differences in the hereditary material, which is the DNA. But with this new ability came problems. Reading a normal fingerprint or recognizing faces does not require in-depth scientific training, but in order to identify the "genetic cluster" it is necessary for the examining laboratory, as well as the legal system, to acquire new knowledge so that irreparable legal distortions do not occur.
What are genetic clusters?
Our hereditary material, found in the nucleus of each of the billions of cells in our body, is almost exactly the same for all human inhabitants of the earth. What is it similar to? that all humans have a nose, a mouth, two eyes and two ears - the same basic structure of the face. But just like the subtle differences in human faces, such as thin or thick lips, sparse or thick eyebrows, eagle noses or a sullen nose, there are also differences in DNA from person to person. These differences are actually responsible for the fact that no two people are completely equal in their characteristics, except for identical twins. All the differences between us - the height, the color of the hair, the color of the eyes, the IQ and maybe even certain behavioral traits - are small differences in the long strands of the hereditary material. It is now known that two people chosen at random differ from each other, on average, in only one of every 1,000 letters of the genetic code, and all the other 999 letters are exactly the same.
How can genetic methods be used for forensic or paternity determination?
Until recently it was very difficult. Initially, the courts needed methods of blood classification or tissue classification. These are "rough" tests, the reliability of which is low. They even require a considerable amount of material, which makes them unrealistic in the event that the identification must be based on a single drop of blood. Only in recent years have real genetic clusters been put into use - methods for direct testing of the genetic code. The tests are concentrated on those relatively rare sites, where high variability between humans is concentrated. These segments are called "polymorphic sites", and there are almost always differences in the code. The in-depth scientific understanding is needed because not all sites include sufficient diversity, and they must be chosen carefully. Furthermore, one must be careful and look at a sufficient number of different sites - so that a court does not make a decision based on the testimony "I saw Lance had brown eyes and dark hair". There are thousands of people whose description is similar. A successful cluster is based on a combination of ten or twenty description details, which together make it possible to distinguish the suspect from among thousands of other people. Many times the courts need to ask the question, what is the probability that the cluster will fit only one person out of a million. Indeed, the advantage of fingerprints is that it has been proven that even if we test a billion people, we will not find two identical prints. But we criminals are rarely allowed to benefit from the use of this method. And as for determining paternity, facial cloisters or fingerprints are not suitable for it at all - the offspring are different from their fathers and mothers. The genetic cluster provides a reliable and excellent solution to the identification problem. But, as mentioned, it requires analyzing differences and similarities in many different sites. For this purpose, the geneticists collected a lot of information about such sites. Site "A" may include three types of cipher (A1, A2, A3); Site "B" four (B1, B2, B3, B4) etc. The genetic cluster of a certain person (in a test based on four sites "A" to "D") will look like this: A1, B3, C2, D5. In another suspect, the DNA tests will show the cluster: A3, B1, C2, D2, and so on.
In a judge's decision on identification, he will need statistical methods, which are very accurate, but difficult for the average person to digest. The situation is particularly serious in countries where a jury decides the case. The trial of OJ Simpson was a prime example of this. The genetic clusteron produced an unprovoked identification, but the jurors preferred to refer to other findings, much less reliable. Analyzing the results requires the kind of calculation skills needed by lottery gamblers: What are the odds that I will randomly pick six numbers that will come up? And why are my chances much higher if I settle for four guesses? So, for example, the chance of making a mistake in a genetic cluster with 16 sites is approximately one in five billion - as many as the number of inhabitants of the entire planet!
An important advantage of the genetic cluster is that it allows the use of a modern method for multiplying hereditary material, called PCR. This is a "chain reaction", in which the genetic material is doubled at each stage, until the amount of DNA is millions of times greater than what we started with. The multiplication is done with a relatively simple device, which allows the criminal identifier to test a tiny amount of material - a single hair, a spot of semen, or a drop of blood. It is also possible to accurately examine old remains, such as a skeleton that was buried in sand for many years. Yes, a genetic cluster test can identify father and son, daughter and mother without any error. Although the similarity of faces between a parent and his offspring may be the subject of a sharp debate between the newborn's aunts, the baby's DNA cluster consists of a precise combination: half of it is exactly the same as the father's cluster, and the other half - the mother's cluster.
If the genetic cluster is so successful - why are there disputes about it? What was America buzzing about for weeks in Simpson's trial, and both sides summoned Nobel laureates to support their version? The reason lies in the lack of regularity, the imprecise use of the method and the talent of advocates to arouse antagonism towards everything that sounds "too scientific". Standardization, minimal scientific training for judges, jurors and lawyers, and strict adherence to correct execution, will in the near future bring the possibility of identification without instigators. The genetic cluster will revolutionize the legal system and strengthen society's ability to protect itself.
