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  #11  
Old 6th May 2017, 05:38 PM
MoberlyDrake MoberlyDrake is offline
mtDNA: T2b5 | Y-DNA: J-M172
 
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Quote:
Originally Posted by lab View Post
What are the odds of not matching multiple 3rd cousins though? I have multiple people I connected with on my tree (before testing) that aren't matching, which seems odd to me but based off what you said could be possible.
Do all of these 3rd cousins share the same parents?
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  #12  
Old 6th May 2017, 05:44 PM
lab lab is offline
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Quote:
Originally Posted by MoberlyDrake View Post
Do all of these 3rd cousins share the same parents?
No, we all share the same great great grandparent, but through different children
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  #13  
Old 7th May 2017, 05:05 AM
DaveInGreece DaveInGreece is offline
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Location: Greece
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One side of my family is extensively tested (26 cousins and growing). We had a case where cousin Simon got his results and his only match was around 9cM with one other cousin, which is such a small amount that it was inconclusive, given that Simon and the other cousin could easily have been distant relatives via some other line of undiscovered shared ancestry. We strongly suspected a "non paternal event".

However, about two weeks ago we got results for cousin Dennis. His match to Simon was above average for the relationship, and he also matched almost all other cousins at or above the expected range. Looking at Dennis's matches in the chromosome browser on Gedmatch you can see that Simon seems to have "freak" results (or the rest of us do, except Dennis) and seems to have inherited "grandma" wherever we got "grandpa" and vice versa.

I can really see this sort of effect looking at my nephew's results on his late mother's side. You'd expect his maternal DNA to be around 25% from each of his maternal great-grandparents, but he actually has a strong bias to his grandfather's side and the results vary from barely 19% from his grandmother's father to over 33% from his grandfather's mother (and that figure doesn't even include his X chromosome which he happens to have inherited entirely from his grandfather's mother). If you imagine that his first cousin (if he had one) might have a similar bias in the opposite direction, they would have a much smaller DNA match than average. Carrying on for two generations (third cousin level) there's a greatly increased chance that the cousins will share no DNA. The estimate that 5-10% of third cousins share no DNA (in significant segments) is based on the averages if you sampled 100s of cousins in 100s of different families, but the figures can be very different within individual families because of the potential for 1st cousins to have a low match with each other which affects the chances of their descendants having a match.

=======
As for the ethnicity... I don't know how far back your tree goes so it's difficult to comment much. But you were expecting French and have Middle Eastern instead? France had an extensive presence in the Middle East and Arab areas of North Africa, so Middle Eastern DNA hidden behind a French surname wouldn't be a major surprise.
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  #14  
Old 7th May 2017, 02:53 PM
lab lab is offline
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Quote:
Originally Posted by DaveInGreece View Post
One side of my family is extensively tested (26 cousins and growing). We had a case where cousin Simon got his results and his only match was around 9cM with one other cousin, which is such a small amount that it was inconclusive, given that Simon and the other cousin could easily have been distant relatives via some other line of undiscovered shared ancestry. We strongly suspected a "non paternal event".

However, about two weeks ago we got results for cousin Dennis. His match to Simon was above average for the relationship, and he also matched almost all other cousins at or above the expected range. Looking at Dennis's matches in the chromosome browser on Gedmatch you can see that Simon seems to have "freak" results (or the rest of us do, except Dennis) and seems to have inherited "grandma" wherever we got "grandpa" and vice versa.

I can really see this sort of effect looking at my nephew's results on his late mother's side. You'd expect his maternal DNA to be around 25% from each of his maternal great-grandparents, but he actually has a strong bias to his grandfather's side and the results vary from barely 19% from his grandmother's father to over 33% from his grandfather's mother (and that figure doesn't even include his X chromosome which he happens to have inherited entirely from his grandfather's mother). If you imagine that his first cousin (if he had one) might have a similar bias in the opposite direction, they would have a much smaller DNA match than average. Carrying on for two generations (third cousin level) there's a greatly increased chance that the cousins will share no DNA. The estimate that 5-10% of third cousins share no DNA (in significant segments) is based on the averages if you sampled 100s of cousins in 100s of different families, but the figures can be very different within individual families because of the potential for 1st cousins to have a low match with each other which affects the chances of their descendants having a match.

=======
As for the ethnicity... I don't know how far back your tree goes so it's difficult to comment much. But you were expecting French and have Middle Eastern instead? France had an extensive presence in the Middle East and Arab areas of North Africa, so Middle Eastern DNA hidden behind a French surname wouldn't be a major surprise.
I've traced back to the late 1700's for most lines. My family has been in America (with the exception of one documented Irish GG-grandfather from Ireland in the mid-1800's) since the late 1700's/ very early 1800's. I don't know if this matters but the French in my ancestry isn't just from one person, it is from multiple people in multiple lines. Any full French ancestors were much farther back than I've traced.

To clarify, I was expecting French and do get approximately ~20% in most calculators, so that isn't actually the problem! The issue is I only get about 30% Northwest Europe on most calculators when I should be getting over 70%.
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  #15  
Old 9th May 2017, 05:54 PM
keigh keigh is offline
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One thing you will need to remember when it comes to cousin matches is that though you match on paper, it doesn't mean that you will match through your DNA.

If you are looking at matches who are at the 3rd cousin on up level this is especially true. My brother and I have different match lists after a certain point. He has 3,406 matches to my 3,127. Of his 3,406, I match only 1,537 and he matches 1,536 of mine. But his cousins would all be mine on paper.

One of his cousins, who doesn't match with me, for example, matches him with 92cM and she also has done her Ancestry testing. At Ancestry we share a DNA circle for one of our ancestors, but we aren't sharing enough DNA to be called an actual match, though we have a paper match. Perhaps if we took our DNA to GEDmatch and lowered the amount of DNA to search for, a match might come up, or it might not.

And as to the amount a person can expect to have showing on the ethnic results, that too, is something that can't be called exactly due to the way DNA is inherited. The only time you get an exact amount of DNA from someone is when you get your 50% from each parent. Your parents don't hand on an exact 25% from each grandparent, and 12.5% from each great grandparent. My brother and I also don't share an exact ethnic estimate either. Don't worry too much about the ethnic results, unless something really unusual shows up. Like a large percentage from a continent that you weren't expecting at all.

The tests are pretty good at giving continental ethnicities, but not so hot on more exact geographic labels. Ancestry gives me 100% European with 52% Great Britain, 10% Ireland, and also amounts from Scandinavia and the Iberian Peninsula, with only a trace amount of 3% for West European. FTDNA gives me as 99% European with 62% West/Central Europe, 32% Scandinavia, 5% East Europe and a less than 2% Finnish (and on paper, I can trace back to a 9th G grandfather who was Finnish). So basically, the tests confirm I'm European, but geography is sort of up for grabs. I think of Ancestry as listing where a large portion of my ancestors were from, and FTDNA shows more where my ancestors' ancestors were from.
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  #16  
Old 9th May 2017, 09:38 PM
lab lab is offline
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Quote:
Originally Posted by keigh View Post
And as to the amount a person can expect to have showing on the ethnic results, that too, is something that can't be called exactly due to the way DNA is inherited. The only time you get an exact amount of DNA from someone is when you get your 50% from each parent. Your parents don't hand on an exact 25% from each grandparent, and 12.5% from each great grandparent. My brother and I also don't share an exact ethnic estimate either. Don't worry too much about the ethnic results, unless something really unusual shows up. Like a large percentage from a continent that you weren't expecting at all.
This is why I drew pause in the first place. The tester gets over 50% middle eastern dna when they should be getting none. Now I know with ancient migrations and the like, it isn't odd to have some admixture with the Middle East, but over half just makes no sense. It's that combined with not matching multiple confirmed (paper) relationships and the fact that this individual is matching people from the Middle East at relationship ranges as close as 2nd cousins when there shouldn't be is what is bringing up questions.
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