mtDNA matches #dna

Jody Gorran

If a person has an extensive family tree that traces back in time hundreds of years directly from his mother, would another person, who has the same haplogroup such as mtDNA K1a4a, legitimately be able to claim those same ancestral DNA relationships to those same ancestors of the other person?

Jill Whitehead

You would ultimately have the same ancestral Eve. It depends how far back your common ancestor lived. Most DNA websites assess how far back your common ancestor lived, certainly on autosomal dna sites, if not on mtdna and ydna sites.

Jill Whitehead, Surrey, UK

Todd Leavitt

mtDNA certainly serves a purpose, but one must be cautious about reaching any conclusions regarding its actual value. My 92 year old mother belongs to haplogroup K1a1b1a, likely the most common group for Ashkenazi Jews. On FTDNA, she has over 425 0-step (i.e. no mutations present) matches! Compare that to my wife (who also turned out to be my cousin, sharing 85 cMs of DNA, probably on our maternal lines) who belongs to haplogroup H3p, and has only 14 0-step matches. Ultimately, both of them will trace back to Ancestral Eve. 


Rollie Stamps
JewishGen ID#51898

I am not an expert on the subject, so I contacted FamilyTreeDNA, due to your issue on the mtDNA sequence. This is their reply :

Thanks for contacting FamilyTreeDNA. At the full sequence level, even an exact match to your DNA (so a match with a genetic distance of zero) would likely share a common ancestor with you on your direct maternal line anywhere within the last 5-16 generations, or 125 to 400 years or so. When you start looking at matches with differences (genetic distance of 1, 2, or 3), those common ancestors can be even further back in time. Once you're looking at matches that are only at the HVR1 and HVR2 levels, it's possible that you could share a common ancestor with those matches anywhere within the last 1000 years. 

Depending on the extensiveness of your tree and your genealogy research, it's possible that your common ancestor could be further back than you have traced your genealogy.

The article I've linked below has a ton of great tips for getting the most out of your mtDNA matches and finding your common ancestor with them. I strongly recommend reading through it.

Hope this helps,


Steven Bloom

For the most part, you would likely not be able to assume this match's ancestors were your *direct ancestors* even along the direct female line that is traced by mtdna. The issue is that the common ancestor is much more likely to be further back than almost anyone can trace.  They would indeed be cousins, and some of them could be direct ancestors, but you can't assume so. 

Stephen Weinstein

No.  It will only mean that you have a common ancestor, but it could be much farther back, perhaps over a thousand years.