Choose the Right Tests

Use the "Simple Rules of DNA" to choose the right test for the line you are tracing.
You have a choice of tests in Genetic Genealogy:
yDNA
mtDNA 
Family Finder 

Here are the simple rules of DNA testing: 

1. Only males can take a yDNA test.  A man you are testing with yDNA must be directly descended from the (male) ancestor you are interested in researching - with no females between them (yDNA cannot pass through a female ancestor). Surname projects use yDNA testing.
2. A female can find a male relative to be yDNA-tested to represent her surname family line.  This can be a father or brother, but sometimes you will have to go back up the family tree and back down to find the right male.  This male must be descended, through males only, from a common male ancestor.
3. A male who is tracing a line that comes to him through a female ancestor will use the same method of going back up the family tree and down again for find a male who descends, through males only, from a common male ancestor.
4. Both males and females can take an mtDNA test.  A person testing with mtDNA must be directly descended from the (female) ancestor you are interested in researching - with no males between the test taker and ancestor being researched (mtDNA cannot pass through a male ancestor) Though not useful in a surname project, mtDNA testing tells you your deep ancestry for your maternal line and can help you find others who share a maternal ancestor. 
5.  Both males and females can take an autosomal (Family Finder) test which tests the DNA received from both sides and is most useful for recent ancestors (6 generations or less going back).
Y-DNA tests
  • Who should I test?
    • Males who take this test are tracing their direct paternal line--their father's father's father's...line.
    • Surname Projects use yDNA tests. 
    • The test taker must be a male, as only males have yDNA.
      • The test-taker could be you, if you are a male researching your own surname.
      • If you are a female you will need to find a male to yDNA test.  He must be descended, through males only, from a common male ancestor in your surname of interest.
      • If you are a male researching a surname line that came to you from a female ancestor, you will need to find a male to yDNA test.
        Sometimes you have to go back up the family tree and come down again to find the right male to test.  

        For example, if you are researching your mother’s surname line, ask these questions:
             Did your mother have a brother?  Did he have a son?
             Did your mother’s father have a brother?  Did he have sons?  Did they have sons?
             Did your mother’s grandfather have a brother?  Did he have sons?  Did they have sons?....and so on.
  • Trying to determine whether a specific male ancestor was of Jewish, Native American or other heritage?
    • you will need to find the right person to test for this specific line. 
    • You need to find a male who is  descended, through males only, directly from the male ancestor of interest.
  • Which yDNA Test?
    • 12 markers:
      • not considered sufficient to confirm a common ancestor, as there are too few markers to compare
      • adequate if you are only interested in your "deep ancestry" (haplotype) or in proving that you don't share a common ancestor with a specific family
    • 25 markers:
      • Only available when ordering through surname projects
      • Adequate if you already know the surname you should match through solid paper trail evidence
    • 37 markers:
      • Considered the best place to start for most researchers
      • Recommended if trying to match without a solid paper trail
      • Many surname projects now require at least 37-marker test to join project
    • 67 markers and 111 markers:
      • Serious genealogists usually end up with 67 markers, some go on to 111 markers. 
      • Confirms matches
      • Defines lineages in a project more definitively
    • Deep Clade
      • Confirms your haplogroup, which FTDNA estimates for each yDNA test
      • Confirms your ancient ancestry and their prehistoric migrations
      • Ordered in addition to your yDNA test
      • Can be added as an upgrade

mtDNA tests
  • Who should I test?
    • Both males and females can take the mtDNA test, which traces their mother's mother's ... mother's line.
    • The test taker must be related, through females only, to the female ancestor of interest.
    • Trying to determine whether a specific female ancestor was of Jewish, Native American or other heritage?
      • You will need to find the right person to test for this specific line. 
      • You need to find a person who is descended, through females only, directly from the female ancestor of interest
  • Which mitochondrial (mtDNA) Test?
      • mtDNA Plus (also called HVR1 + HVR2)
        • Provides information on your deep ancestry
        • Can confirm you and another person share a common maternal ancestor
      • mtDNA Full Sequence (includes HVR1, HVR2 and FMS)
        • Provides information on your deep ancestry
        • Can confirm you and another person share a common maternal ancestor
        • Tests all of the mtDNA, highest level of mtDNA testing
        • FMS matches within the past 16 generations

Family Finder tests (autosomal or atDNA)
  • Who should I test?
    • Both males and females can take the Family Finder test.   
    • Adoptees can use this test to help find biological relatives.
    • People who have taken the yDNA or mtDNA test can use atDNA to better define relationships.
    • The atDNA test is most useful in finding relations up to 6 generations back, but is not able to confirm more distant ancestors.

Sometimes a female has to climb up the family tree and then back down again to find a male to yDNA test for her family line!