Common ancestor born 1701??

[YorkshireBorn]

I have a DNA match and we share 9cM across 1 segment. They have a pretty large tree, most of it is fully sourced. I looked through and they have my x8 great grandparents as direct ancestors. I'm assuming this is where the connection is but would such a far away connection be possible to detect? Our supposed common ancestors were born in 1701 and 1705.

[clayton bradley]

I have been told you can only trust autosomal back to 1750 ish but recently I identified on Ancestry a dozen 9th cousins (all related to each other in America- I am in England) from 24cM down and our MRCA was mid 1600s. The MRCA was actually in the Netherlands. I was surprised to think you could get such high matches for so long ago.

[brigidmac]

Yes
I have paper work that confirms DNA match of my mother that links her great great grandfather born around 1800 to one of his 6x greatgrand sons 9cm .match

Also have an 8cm match which links back to 1750's ancestor

If you have youngest child of youngest child or children born of older parents across the years .. the date span will  cover fewer generations so your DNA link will be stronger if that makes sense

For example one of my great grandparents was born 1840 my grandfather b 1903 being one of youngest .
His half siblings would be considered a generation older but genetically they were same generation .

Another great grandparent was born 1880 
Her son b 1906 had children in 1930.'s but another in 1960.'s
+ His son her grandson had children were born in the 1980s so are over 100years apart from one greatgrandmother but under 60 years apart from another great grandmother.

[Petros]

I have a number of matches (not all confirmed) in the 6-9cM range to one set of 5 x great grandparents born 1727  but no confirmed matches to any other 5 x great grandparents. Matches to a 4 x great grandparent, born 1751, are in the same low cM range