I've submitted mine to
FamilyTreeDNA as you say the more data is collected the more likely matches will be made. That site provides 3 major types of test, which are effectively
- male only line test, going back son to father to grandfather etc etc. Known as Y-DNA
- female line test, going back son or daughter to mother, to grandmother etc,etc. Known as mtDNA
- a mixed test, going back on all lines but for very limited number of generations
The Y-DNA test often regarded as a surname test is the basis for surname projects, I've joined the Bisset project (as the 2nd member of the project) and to our surprise when the results come back we found that the project leader and I were cousins. We know of no paper link and my line I have back to 1684 his line is back to 1740s based around 20 miles away in a different county. Since then we have had numerous other people join the project and have found several other close matches however again no paper trail established. One of these matches is for a line in Edinburgh area some 120 miles away from our Aberdeenshire lines so we aren't sure where that fits in either. So we continue to encourage more submissions of tests from Bisset males to try and add more pieces of the jigsaw.
The mixed line test that they call Family Finder has been disappointing. The matches are fairly weakly defined as a little thought makes you realise...
You get ~50% of your DNA from your father and ~50% from your mother as they do in turn from their parents.
Now think of this if we only had 2 DNA pieces instead of millions you could think of it this way, your father may have DNA pieces called AB and your mother CD. You could have inherited AC, or AD or BC or BD. If you have 4 siblings then there is a fair chance you would each have a different combo. Now in reality of course we have billions of DNA letters and so the combinations are immense but 50% of those letters still come from your father and 50% from your mother.
So as you go back generations you find that the match even between close relatives gets weaker and weaker, you may almost no DNA from one of your grandparent. eg:
Grandparents AB & CD (fathers side), EF & GH (mothers side), now your father could get BD and your mother get EH, you could get BH. So that's a 50% of DNA from 2 grandparents and none from the other 2. That's of course extreme with only 2 DNA letters rather than billions and so random chance with a billion coin toss 50/50s like that will be that the percentages from your 4 grandparents might be 5%/45%/30%/20%.
So this technique gets less and less likely to have enough data to make a match the more generations you go back and indeed the company suggest its no more than half a dozen or so generations. However that's still 4th/5th ish great grand parents, do you know ALL 128 of your 5th great grandparents, will someone you match know ALL 128 of theirs so you can pinpoint which branch the match is on?
Typically no so the family finder test doesn't show much. That plus the vast majority of people who have taken the test haven't actually uploaded any tree data so you with absolutely nothing to go on you have no earthly clue where the match might be. Worse some people don't even sign the form to allow match results to be made known so all you know is there is a match at some level but you can't see where because their data is withheld. Which is so utterly pointless you wonder why they took the test in the first place.
