How far back to find a common ancestor

[Flemming]

Just wondering how far back in time people have gone to find a common ancestor with a shared match, and also the level of cM shared with them.

Have people gone back into the 1600s, and would this be for quite low levels of match?

Interested to hear people's experiences with this.

Thanks, Flemming.

[Mike in Cumbria]

A shared ancestor in the 1600s would give a negligible level of shared DNA.

[DavidG02]

I have a paper match to a sister ie Common Ancestor is their parents - from my Paternal line

My ancestoral grandmother was born 1783

8cm across 1 segment

There does need to be caution BUT I have that size DNA  match to this person who is a PAPER match to a family name.

It could be elsewhere

I also have a match through this same ancestoral grandmother from her 2nd marriage ie I match through her alone and this one is 20cm across 1 segment

[Gadget]

I've just checked and I have two 5th cousins with 6cM .They match via Common Ancestors and paper trail. Our common ancestors were 4 x greats - born 1737 and 1749.

Gadget

[Gadget]

I've now checked all the 6cMs who are listed in the Common Ancestors  and with a verified paper trail. The earliest is  a common 5 x great b, 1715.

Gadget

[Petros]

Much to my surprise I discovered that my wife and I are related through a couple born in 1751, 4th cousin twice removed for me, sixth cousin twice removed for her. This doesn't reach Ancestry's DNA threshold for a match.

Thrulines throughs up matches for me to this couple but only to their daughter for my wife.

[Flemming]

Thanks for all the replies, very interesting. Like David, I have a reverse sort of situation where the descendant of a 2x great gran's offspring (a half third cousin) matches at 9cM, whereas the descendant of a 5x great gran's offspring (a half sixth cousin) matches at over 20cM (this is on Ancestry). Both of these matches are in the same direct line with the 2x great gran born in the 1820s, and the 5x great gran born in the 1740s.

Interesting that Gadget has a match back to 1715 which gives encouragement to keep going that far with the paper trail. I recall reading in an unrelated thread that someone found a match back into the 1600s and wonder how common this is.

Petros - I find more and more that my maternal and paternal lines have intermarried, even across some fairly wide geographies. Also that siblings have different matches which all goes to show, I suppose, the weirdness of DNA.

Thanks again to all.

[Taylor94]

The furthest DNA match with paper trail I have with someone is through my 8th grt grandparents both born 1710 and 1711.
They are my 8th grt grandparents and my matches 6th grt grandparents so I think we are 7th cousins 2x removed. Ancestry says we share 8cm across one segment.

[GenesA]

I have found three DNA matches, all descended from the same couple who had been born in 1731 and 1745. They are the earliest examples but I have another one descended from a couple born 1781 and 1784.