First, I didn't really go into the scientific details of the test in the previous post. My DNA test results were matched to other folks' results. Here's how FTDNA explains it:
"Family Finder detects your near and distant cousins by comparing your autosomal DNA with that of other Family Tree DNA customers. If two people share identical segments of DNA then they may share a recent ancestor. When the Family Finder program finds matching segments, it uses statistical methods to determine if the segments are likely to be Identical By Descent (IBD). If they are determined to be IBD then the Family Finder program calculates the relationship based on the shared segments’ number and size. The Family Finder program declares a DNA segment to be Identical By Descent (IBD) if it contains at least 500 matching SNPs (Single Nucleotide Polymorphism) in series. A DNA segment (block) that is 10 centiMorgans (cM) or larger indicates conclusive shared ancestry while a block that is between 5 and 10 cM is highly suggestive of shared ancestry. Additional factors such as the number of shared blocks that are at least 1 cM and their size are also used for the degree of relatedness calculations." |
It's all very scientific isn't it? This explains the two numbers on the matches page (Shared cM and Longest Block). It also helps explain what I'm looking at on the "Chromosome Browser" Page. I showed both of these screenshots shown in the previous post.
I should say at this point: I have yet to receive notification from FTDNA that I have any FF test results or matches. I only knew about these matches because I've been checking for results. I'd expect better communication from FTDNA on this...
So, my results gave me one predicted 3rd cousin and four predicted 4th cousins. If these estimates are accurate, I might be related to these matches through my 2x and 3x Great Grandparents. The match for 3rd cousin has a larger number of shared cM than the 4th cousin matches, at 45.56, with the longest block being 19.41. Based on FTDNA's explanation, this looks like a very good match. I didn't recognize any of the surnames listed for this match, but it doesn't look like that many are listed.
I went ahead and emailed all of my matches (the five "close relatives" as well as the more distant "speculative" ones). I sent them a prepared letter listing my surnames, website and contact information. I was shocked by the almost instant response I received. Within a few hours I had received emails from all of my close matches and a few speculative matches. So far, there haven't been any instant connections, which I also found surprising. This test is supposed to find matches within six generations - which I have almost fully charted. But with no obvious ancestor found yet, the shared ancestor is obviously more ancient than that. My matches and I are all exchanging pedigree files to look for a more hidden connection.
And, although we're not matching names, we are matching geographic locations. Three of my close matches have family in many of the same locations as mine. We might be able to focus on researching certain lines where both of our trees show up at the same place and time.
Based on comments from others, I should continue to make matches as other folks receive their test results. I'd love be able to make an easy match - instant gratification and all that. But, these difficult to make matches will probably help my research more than an easy match. Fingers cross either way!
2 comments:
Thank you for sharing all of this with us. I am trying to get a cousin (the last male of my grandfather's line) to get a dna sample for Family Tree. He is an elusive cousin to say the least. Thanks for reporting on your progress.
I'm glad you are getting some matches already!
Hopefully, since you got these distant matches so quickly you will get closer ones in the future. Also, it is nice that everyone responded and seems as interested as you are.
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