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  #1  
Old 24th October 2017, 04:27 AM
Ivar Kristensen Ivar Kristensen is offline
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Y-DNA matches with a genetic distance of 6 and 7. How certain can I be?

Hi. I only have two 67 marker matches, both from the British Isles, which is a surprise to me as my earliest known ancestor, Niels Willumsen Storalmenning (b. 1620), lived in the northern part of Norway. (See https://www.familytreedna.com/public...frame=yresults)

These matches are, however, at a genetic distance of six and seven steps.

I also have a 37 marker match with someone from Scotland, at a genetic distance of four steps. But he only tested 37 markers.

How certain is it that we actually share a common ancestor within the timeframe given in the TiP report? Could it, perhaps, be a spurious resemblance?

Thanks in advance,

Ivar
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  #2  
Old 24th October 2017, 09:01 AM
spruithean spruithean is offline
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You probably do share a common ancestor, but not in any recent timeframe. Could be 1000s of years ago.
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  #3  
Old 24th October 2017, 09:04 AM
John McCoy John McCoy is offline
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I would not want to base any genealogical conclusions on such a match.
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  #4  
Old 24th October 2017, 09:45 AM
Ivar Kristensen Ivar Kristensen is offline
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Quote:
Originally Posted by spruithean View Post
You probably do share a common ancestor, but not in any recent timeframe. Could be 1000s of years ago.
But the Tip calculator reports 88,45, 88,95 and 97,57% probability that I share a common ancestor within 16 generations. Am i being mislead by FTDNAs calculations?

And why are there no matches with people from Scandinavia at 37 and 67 markers?

My haplogroup is I-M223>M284-Isles/Sc.

Last edited by Ivar Kristensen; 24th October 2017 at 09:48 AM.
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  #5  
Old 24th October 2017, 09:47 AM
jova99 jova99 is offline
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99%

The TIP calculated is pretty accurate at 67 markers.

there is a 99% probability you have a common ancestor within the last 24 generations, or within the last 700 years with your 67 Marker matches.

have they done the 111 marker testing ? This would be more accurate.

24 generations ago you would have 16,777,216 Great Grandparents, so it is not very meaningful to determine your ancestry. It is possible that one of your 16 million Great Grandparents was from the British Isles and the others were from another area. Also possible some of your ancestors migrated to the British Isles, via the Norman invasion. The The Norwegian king Harald Hardrada invaded northern England in September 1066 and thus many from the UK will have Y chromosomes from the Norwegian invaders..
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Old 24th October 2017, 10:01 AM
The_Contemplator The_Contemplator is offline
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Originally Posted by Ivar Kristensen View Post
And why are there no matches with people from Scandinavia at 37 and 67 markers?
Maybe not enough people from there have tested. Maybe that lineage is no longer at Scandinavia. Maybe it "daughtered-out", meaning they stop having sons so the Y-DNA from that specific group was not passed down.

You could try to find distant paternal cousins or potential cousins and get them to test to see if they match you. There is also the possibility of an NPE (non-paternity event) where someone raised a son that was not biologically their own.
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Old 24th October 2017, 10:31 AM
Ivar Kristensen Ivar Kristensen is offline
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Originally Posted by jova99 View Post
have they done the 111 marker testing ? This would be more accurate.
The person I match with a genetic distance of 6 steps have. And his last name is supposedly of Norman origin http://www.bartlettname.net/england.html

The problem with the norman theory is my haplogroup. I-M223>M284 is very rare in Norway. Just look at the results from the I-M223 project. I'm in the middle of a bunch of people from England, Ireland and Scotland.

Last edited by Ivar Kristensen; 24th October 2017 at 11:24 AM.
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  #8  
Old 24th October 2017, 10:48 AM
Ivar Kristensen Ivar Kristensen is offline
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Originally Posted by The_Contemplator View Post
You could try to find distant paternal cousins or potential cousins and get them to test to see if they match you.
That's what I'm trying to do. Without any luck so far.

Quote:
Originally Posted by The_Contemplator View Post
There is also the possibility of an NPE (non-paternity event) where someone raised a son that was not biologically their own.
I have been speculating a lot about that after I got my results

Last edited by Ivar Kristensen; 24th October 2017 at 11:11 AM.
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  #9  
Old 24th October 2017, 12:08 PM
TwiddlingThumbs TwiddlingThumbs is offline
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Quote:
Originally Posted by Ivar Kristensen View Post
These matches are, however, at a genetic distance of six and seven steps.

I also have a 37 marker match with someone from Scotland, at a genetic distance of four steps. But he only tested 37 markers.

How certain is it that we actually share a common ancestor within the timeframe given in the TiP report? Could it, perhaps, be a spurious resemblance?
FTDNA's "matches" list shows a lot of matches that FTDNA does not consider as a "match" under it's genetic distance interpretation guidelines. Depending on which version of FTDNA's guidelines you look at, a GD of 6 or 7 on a comparison of 67 markers or a GD of 4 on a comparison of 37 markers means that, for men who share the same surname, they probably have a common ancestor in the genealogical time frame (which FTDNA defines as 15 generations). See 67 marker guidelines and 37 marker guidelines. The implication is that a GD or 6 or 7 on a 67 marker comparison or a GD of 4 on a 37 marker comparison does NOT mean that the men two men probably share a common ancestor within the genealogical time frame. As the guidelines state, the fact that men do or do not have the same surname is important information that shifts the probabilities. If two men do not have the same surname, the chances are significantly greater that the "match" is the result of convergent mutations of STRs. The same logic should also hold for TiP calculations, so I would discount the TiP probabilities if the surnames are different. There is no doubt a relationship somewhere in the past, but could be 1000s of years.

The most likely reason you have matches from the British Isles and none from Norway is that a lot more men from the British Isles (and certainly of British Isles descent) have been tested at FTDNA.

Last edited by TwiddlingThumbs; 24th October 2017 at 12:13 PM.
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  #10  
Old 24th October 2017, 12:25 PM
Ivar Kristensen Ivar Kristensen is offline
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Ok, thanks TwiddlingThumbs!

"5 or 6. Related. A 61/67 or 62/67 match between two men who share the same surname (or a variant) means that they may to share a common ancestor within the genealogical time frame. The common ancestor is probably not recent, but may still be within the range of most well-established surname lineages in Western Europe."

I don't get why they have to share the same surname (or a variant). Doesn't surnames change completely in many cases?

Last edited by Ivar Kristensen; 24th October 2017 at 12:33 PM.
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