bigsnake49
Regular Member
- Messages
- 1,880
- Reaction score
- 471
- Points
- 83
- Ethnic group
- Thracian
- Y-DNA haplogroup
- R-PF7558 (LDNA)
- mtDNA haplogroup
- U5a1b1d1 (LDNA)
10cM, 20cM? Anybody knows?
-
Don't want to see ads? Install an adblocker like uBlock Origin or use a Europe-based privacy-friendly browser like Vivaldi or Mullvad.
At what shared DNA threshold are the DNA matches noise?
- Thread starter bigsnake49
- Start date
TardisBlue
Regular Member
- Messages
- 161
- Reaction score
- 57
- Points
- 0
- Ethnic group
- Cheesy macaroni
- mtDNA haplogroup
- W3a1
It depends, IMO. I personally pay more attention to the length of the segment than to the sum of shared segments. The longer the segment, the more interesting. That's why, personally, I'd take notice of a 14 or 15 cM shared segment, but would probably discard 2 shared segments of 7 cM each… unless there's genealogical evidence of shared ancestry, like ancestral names in common, or ancestors sharing the same birthplace. From what I've read, a shared segment >15 cM generally means the match is real (IBD), or rather, there's like 90% chance that it is. But of course, it doesn't mean that if you share a smaller segment, it's necessarily a false match. The only way to find out is for you and your potential match to both work on your genealogies to find a most recent common ancestor.
The longest the cM the nearest in time to your ancestor´s line (most probable).
There is a common mistake when people think about the length of segments. A 4cM segment could be totally valid and plenty of segments can pass generations unaltered.
There is a common mistake when people think about the length of segments. A 4cM segment could be totally valid and plenty of segments can pass generations unaltered.
And your reasoning?