View Full Version : How many matches?

12-14-2013, 01:23 PM
I was just wondering how many matches over 7cM you would need to infer ancestry from a particular country if that's possible? I know with migrations and genetic similarities between countries it can be difficult but there must be a point where you have a number of matches that begin to share a country in common? I must also add this is to help someone who does not know their full family tree and is using DNA testing to find clues.

R. Walker
12-15-2013, 11:41 PM
All that you can tell from matches is that the people who match are among the few descendants of the thousands of people you are related to in distant times who have tested. Who lived all over the place. It just depends who tested. The three sites are heavily weighted by testees of British Isles and Ireland, with German probably next. Remember countries have changed over the past recent history. This is the type of genealogy better done on paper by tracking down ancestors. Before paper? I don't know if there ever will be a way to tell, even following mtDNA or yDNA. Our European ancestors were all over the place.

12-16-2013, 04:27 PM
Thanks. So if someone knew they were half British half unknown American (and their British side appears to be solidly British) and they had compared their results with 100% British people and noticed that they have 12 cousin matches over 7cM from a country in Central Europe and the 100% Brits didn't share any matches to this country then that would not be indicative of some ancestry from that region at some point in the past? I'm trying to work out how autosomal cousin matches can actually be of benefit to people without a paper trail.

09-20-2016, 07:10 PM
Hi Boudicca I am 100% northern English for ~10 generations and with the 2000 matches limit in GEDmatch set at 7cM I only get down to 8.5cM. In the trees that I have pursued of my matches I have not seen a single Central Europe name other than German and Hungarian in a USA tree, no modern Germans or others. I would consider it a more accurate guess of your unknown ancestry than ftdna or 23&me origins algorithms. But it is only a guess!
If you get matches from the less affluent EU countries then they are more likely to be real, because the number of people testing us lower. The Finns however are heavy testers compared to country size.
Have you also tried the GEDmatch other calculators eurogenes etc?
But as someone else said in the end only the paper trail will tell you, the rest is just clues and hints. Good luck!