Thursday, June 9, 2011

So you're thinking about doing a genealogical DNA test...

This is my latest installment of my collection of posts related to FTDNA's FamilyFinder test.

I've received several questions over the past few weeks about doing autosomal DNA tests, and one of the most common is: Which test is better - FamilyFinder or 23andMe??

Unfortunately the answer is not that simple.  My honest advice is that doing both is likely your best option, though I understand the costs involved with going through two separate tests (especially if you are having your mother tested as well).

So I'm going to break down both tests and leave the actual decisions to you.

Both tests use similar platforms, Illumina (but slightly different microarrays), to test and analyze DNA so there is little concern that the results and the accuracy of one is better than the other.  However, beyond that they take very different paths.

FamilyFinder (by Family Tree DNA)
  • FF test is designed specifically to find relatives on all lines
  • Designed for the genealogical community
  • Database size: ~10,000
  • FTDNA tests both autosomal and Y-STR (for males) providing more insight into paternal side
  • All matches have signed the waiver to set their information to "public" for their matches
  • Ancestral surnames and GEDCOMs (family trees) of matches are displayed
  • Email addresses of matches are displayed
  • Matches are much much more willing to respond to contact
  • Much higher threshold of shared DNA before a "match" is acknowledged, thus better (closer) matches
  • Population Finder feature is only in beta version so it's very sketchy in identifying actual ethnic makeup correctly
  • Created a new algorithm to compensate for the high number of intermarriage in the Ashkenazi population

RelativeFinder (by 23andMe)
  • RelativeFinder is only one aspect of the 23andMe test
  • Designed not just for genealogy, but also individuals seeking medical information
  • Database size: ~ 80,000 to 90,000
  • Does not test Y-STR or mtDNA -- however for DC adults, health information is very valuable
  • Ancestral surnames are hidden unless the person clicks public option within their online 23andMe profile
  • Must contact matches through 23andMe's private messaging system - no email addresses provided
  • Only allowed to contact 5 new matches a day through the private messaging system
  • Matches are much less willing to be contacted - many only do the test for health information
  • Ancestry Finder is a much stronger program to identify "deep-clade ancestry"
  • Acknowledged skewed results for those with Ashkenazi ancestry, but has not yet tried to create a new algorithm to accurately determine cousinship

Bottom line: 
FamilyTreeDNA's FF test has a significantly smaller database so the chances of getting a close or immediate relative are smaller, but the matches you have will be more willing to respond.  And those that don't you still have their name and if they listed ancestral surnames/locations (this can be helpful, as many non-responders still have their family trees public on

23andMe's RF test has a significantly larger database (especially including many more Europeans), so the chances of getting a close or immediate match are better, but those matches are going to be in general less likely to respond.  And since their names and ancestral surnames are hidden there is little chance of getting information from non-responders.

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