How to Explain the Results of a Genealogy DNA Test
Genealogy DNA test results are used to determine how two or more individuals are related through a distant common ancestor. There are two types of DNA tests used for genealogical purposes. The Y chromosome DNA test is for males. The Mitochondrial DNA, or MtDNA, test is for females, as they do not posses a Y chromosome. Explaining the results for either type of genealogy DNA test follows the same procedure.
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Instructions
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Reading a Genealogy DNA Test
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Explain the four markers, or nucleotides, that make up the human gene sequence. Elaborate that these markers are examined and compared to the Cambridge Reference Sequence (CRS). The CRS is the standard set of modern human DNA that all DNA test results are compared to. It is the modern human DNA sequence without mutations. The letters that represent the nucleotides are A, T, C and G. A particular genealogy is determined by comparing the sequence of a particular test to the CRS. Depending on the sequence of the DNA, a haplotype or haplogroup is assigned.
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Educate the person or group about haplotypes and haplogroups. Explain that these terms are used interchangeably. Teach that the haplotype or haplogroup is a group of individuals who have a similar DNA sequence. Haplotypes are assigned a letter, or a combination or a letter and a number, such as M or L2.
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Tell your audience about the three types of mutations, or deviations, from the CRS. The first and most common is a substitution or transition. This is when one of the nucleotides or markers is replaced with different marker. For example a C is replaced with an A, C, or a G. The next type of mutation is called a transversion. This is when a C or a T is replaced with an A or a G, or the other way around. The third and least common type of mutation is an added or missing nucleotide.
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DNA sequences can identify groups of people with common ancestry. Explain how to use the information contained in the genealogy DNA test to trace your ancestry and family migrations. The company that performed the genealogy DNA test will give you a printout of your results. These companies have a website where you can register your test results and compare them with the results from others. Use the information to find individuals with a common ancestry. Another possibility is to set up a new group study for family surnames not yet listed on the company's website.
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References
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