For the most part, genealogical research has depended, to a great extent, on written resources, such as census returns, registration certificates, and church records. Additional sources, like elderly relations, tax assessments, and judicial records, are quite popular amongst genealogical historians. Recently, however, DNA fingerprinting is turning into a rising star among genealogical enthusiasts. Called “molecular genealogy,” DNA fingerprinting can be used to determine links between far-removed cousins or to find out to which large last name “clan” a person belongs.
What is molecular genealogy or DNA fingerprinting?
Every person on the planet has the same chemical structure of DNA. The difference between one person and another is the order of the base pairs—the proper name for two sets of nucleotides which reside on opposite ends of a DNA strand. Because of the millions of base pairs in any given person’s DNA, each person has a different base pair sequence.
A sequence of base pairs is not the only way to identify a person. Because there are millions of them, determining a person using solely base pairs would take an enormous amount of time.
That is why DNA fingerprinting relies on repeating patterns of DNA. Rather than providing an individual genetic fingerprint, DNA fingerprinting figures out whether two DNA samples are from the same person, relatives, or non-relatives. By examining only small DNA patterns, scientists look for specific patterns and use them to determine the likelihood, or “closeness,” of the relationship (or non-relationship) amongst people.
What does DNA fingerprinting do?
Thus, the phrase “DNA fingerprinting” or molecular genealogy is, in and of itself, a misleading term: rather than being a DNA pattern that is wholly unique to a specific person, DNA fingerprinting actually only indicates the probability of a person’s relation to another person or, even, to him or herself.
What is examined in DNA fingerprinting?
Tests of molecular genealogy or DNA fingerprinting examine the standard markers on “junk DNA”—--either on a man’s Y-chromosome (which is passed from father to son) or within mitochondrial DNA (which is passed from a mother to her children). Such markers are important because they undergo very little changes over the span of generations, and, although DNA fingerprinting in a genealogical context cannot identify a person or prove paternity, it can demonstrate the likelihood of two people being related by paternal or maternal ancestry.
How does DNA fingerprinting apply to genealogy efforts?
Genealogical experts say that molecular genealogy should be one of the last portions of a genealogical search—after as much as possible has been determined from the memories of family members, personal accounts, and public records. Molecular genealogy can provide data that either verifies or negates purported branches of a family tree. When supplemented by existing genealogical records or research, molecular genealogy is especially useful when circumstantial evidence supports a connection but no documentation can be found.
At this time, there are a growing number of last name studies being conducted; these tests identify and categorize genetic sequences of groups of people with the same last name and determine the extent to which they are related, as well as ancestry. Ultimately examining whether families with the same last name have the same or different origins, researchers seek to identify the geographic areas from which these families may have originated. By coupling these studies with traditional genealogical data, there are new areas in which to examine current sources.
