With DNA analysis as in CSI:Miami you cannot only convict a criminal and relieve an innocent defendant. Today, modern genetics are also used to determine ancestors and their descendants.
All people have more than 99 percent of identical genetic material. Consequently, only a very small part of our DNA makes us unique and is relevant for our physical characteristics such as the color of our eyes, predispositions to diseases etc. Apart from that, we share certain genetic traits with our biological relatives. You could call them our “family genes” that are passed down from generation to generation.
DNA In Every Cell of Our Body
Every father passes on his Y chromosome (Y DNA) to his sons, while mothers pass on the so-called mitochondrial DNA (mtDNA) to all of her children. Genealogy utilizes this scientific knowledge by way of comparing the Y-DNA or mtDNA of two test persons in laboratory tests and then check if they match. In practice, usually an oral smear is taken from the inside of one’s cheek. Although our DNA is not only in our saliva – actually, it is in all cells of our body – the removal with the now well-known extra-long cotton swabs is the simplest and a painless method.
Who Uses DNA Testing?
Anyone who has, for instance, located a supposed distant relative, but all written records have been destroyed by fire, war or natural disasters, thus gets the chance to prove a relationship or – in case of a negative result – one is able to unmask it as a legend. Nevertheless, beware: every person has the right to informational self-determination. This also includes his genetic information. In addition to cell material, a written consent of the alleged relative is required.
Nevertheless, even genetic genealogy has its limits. It will not be able to replace “traditional” research at the archives. First, the procedure only works if corresponding DNA samples are available. Secondly, consanguinity has to be uninterrupted. Adoptions, for instance, complicate matters and render DNA testing pointless (when researching the name-bearing ancestors).