Ancestry DNA testing does not refer to a single test but rather to a number of different DNA tests each aimed at providing specific information about your ancestry. Amongst the ancestry tests available are the maternal lineage and paternal lineage ancestry tests.
Y-STR ancestry test: the test will examine Short Tandem repeats (identical sequences on DNAs) and determine which population or group these sequences come from. Group or populations that share the same genetic information are called a haplogroup and originate from the same geographical regions. The test will link you to your ancestral regions and to the populations to with which you share your genetic information.
MtDNA ancestry test: you biogeographical origins specifically tracing back your maternal ancestry can be done by means of this test. MtDNA test results for ancestry will show a map linking you to your haplogroups and thus, showing your ancient maternal origins with reference to specific groups of people who share your same MtDNA patterns.
Genealogical research and family tree studies: ancestry and genealogy are of course two closely related fields. Genealogical research can either be carried out by a genealogist or you can undertake you own little study by doing your own research. Whilst ancestry testing will help you discover your origins, if you wish to hone in onto your family tree and get a more in depth picture of your genealogy and the names of your forefathers, an ancestry test will not do.
Ancestry using Relationship DNA tests: helping you find relatives and link you to specific people
Discover your ancestors with a DNA test and you can find whether you are truly related to a specific person or whether you share a common paternal or maternal line with someone. In this case, you may wish to have a DNA test between two or more people and send DNA samples of all the people involved for analysis.
If you wish to establish whether you share a common maternal lineage with another person you will need to do an MtDNA test. MtDNA, or mitochondrial DNA, is rarely affected by mutation and your MtDNA will be the same if you share the same maternal line. MtDNA is inherited by both male and females from their mother but only females will pass it to their children.
An MtDNA test will only tell you whether you share a common maternal line with another person however, it cannot tell you the exact nature of the relationship. The test will not tell you ‘this person is your mother/aunt etc’.
A Y-chromosome test in relationship DNA testing: Males have an XY chromosome pair and females have an XX chromosome pair. The Y-chromosome will be unchanged as it is passed down the male line. If you have a half brother with a different mother, the test can establish whether you share the same father by analyzing your Y-chromosome patterns. A Y-chromosome test with a suspected male relative can also tell you whether you are truly related and share the same paternal line.