People who are interested in using DNA analysis to assist with their genealogical research can choose from a variety of different genealogical DNA tests that are offered by Family Tree DNA. Family Tree DNA was founded in 1999 and is located in Houston, Texas. The company specialises in providing DNA testing services with a focus on genealogical applications.
There are three primary types of genealogical test, each with different features and limitations that depend largely on the biological inheritance properties of the type of DNA in question. Each of these three types of test is described below.
The “Family Finder” DNA Test
This test is available to everybody, whether male or female. It analyses a huge number of autosomal DNA markers that are scattered across chromosomes 1 through 22 and then looks for blocks of identical DNA that you share with other people who have also had this test done. If you share large enough blocks of DNA with somebody else, then that indicates that the two of you are related in some way. As the number and size of these shared blocks increase, the closer that this relationship is likely to be. Note that the connection can lie anywhere that the pedigrees of two matching people overlap.
When you take the Family Finder test, you are provided with a list of the people that share segments of autosomal DNA with you, along with information on your shared segments and an estimate of what degree of relationship might exist between you. As a real example, two members of FHSNL were put in touch with each other because they shared moderate-sized DNA segments on two difference chromosomes. When they then compared their pedigrees, they discovered that they are third cousins who separately descend from a son and daughter of a couple that were married in Harbour Grace in the 1830s.
An extra feature of the Family Finder test is that it also compares your DNA to that of several reference populations from around the world. Based on which of these populations your DNA segments are most similar to, an estimate of your continental genetic origins is provided. As an example, a FHSNL member from Bonavista Bay was found to be about 97% European and 3% Native American in origin.
Some more information about the Family Finder test can be found by clicking here. Also, the Family Finder test was the focus of the May 2011 FHSNL Lecture (slides and an audio recording of the lecture are available here).
Anybody who takes the Family Finder test and has ancestry from Newfoundland and Labrador is encouraged to join the Newfoundland and Labrador Family Finder Project.
Mitochondrial DNA Tests
Everybody has mitochondrial DNA (“mtDNA” for short) and so everybody is able to have their mtDNA analysed. Only women pass their mtDNA on to their children, and so the mtDNA that you carry would have been inherited from your direct maternal line (i.e., from your mother’s mother’s mother’s … mother).
Family Tree DNA’s “mtDNAplus test” analyses about 1000 markers that are located in what is called the HVR1 and HVR2 regions of the mtDNA genome, whereas the “full sequence” test (which is the best option) involves a complete analysis of all 16500 markers that make up your mtDNA genome.
Any two people whose direct maternal lines descend from a single woman who lived within the past few hundred years should have identical mtDNA test results. However, people who have identical test results could potentially be more distantly related, especially if all that they are comparing are test results for the HVR1 region. Note here that two people who have identical HVR1 test results might have differences in the other parts of their mtDNA. Because mtDNA mutations are very rare, such differences would rule out a close connection along their maternal lines.
There is a Newfoundland and Labrador mtDNA Project that you can join if your direct maternal ancestral line involves Newfoundland and Labrador.
Only men have a Y-chromosome, and so only men can do Y-DNA tests. The Y-chromosome is passed directly from father to son, and so a man’s Y-chromosome can be traced back through his direct paternal line (i.e., his father’s father’s father’s … father).
Family Tree DNA offers a basic 12-marker Y-DNA test as well as tests that focus on 37, 67 or more markers. Any two men whose direct paternal lines both descend from a man who lived within the past few hundred years should have identical (or very nearly identical) Y-DNA test results. Note, however, that the markers involved in Y-DNA tests are prone to occasional mutation, and so the Y-DNA results of two related men can sometimes differ on a few markers. So when comparing the Y-DNA test results of two men to see if they are related along their direct paternal lines, it is advisable to test and be able to compare as many markers as possible (ideally at least 37).
When a man has a son, the son usually inherits the man’s surname along with his Y-chromosome. Hence Y-chromosomes tend to correlate with surnames, which in turn has led to a proliferation of surname-based Y-DNA projects. You can search to see if such a project exists for any of your ancestral surnames by using the “Surname Search” form on the right side of the Family Tree DNA webpage, or by clicking on “Projects” at the top of their webpage.
If there isn’t already a project for your surname, then you have the option of starting one. Note that the following surnames have Y-DNA projects at Family Tree DNA that are being coordinated by members of FHSNL:
More information about genealogical DNA testing can be found on the Wiki for the International Society of Genetic Genealogy. A variety of webinars about genetic genealogy are also being offered by Elise Friedman of Relative Roots.
You can also direct inquiries about DNA testing to FHSNL board member David Pike at firstname.lastname@example.org
An interview that David Pike did with Rogers TV in 2010 can be viewed by clicking here.