Firstly are several Nankivells with established paper trails who tested as Z16294.
A descendant of Francis Nankivell and another descendant of his brother Robert Rogers Nankivell were tested and matched the Nankivell Z16294. Further testing against other Nankivells revealed that they were descendants of Samson, one of the 4 sons of Robert Nankivell 1650-1707.
This is what we set out to do as it was difficult to prove Thomas Nankivell's paternity when so many Thomas Nankivells had been born at the time in St Agnes, Cornwall. Also, many of these families moved to Devon following mining employment.
We knew that Thomas Nankivell, father of Robert Rogers Nankivell and husband of Ann Rogers, died in 1849. Now we know he was born in 1787.
No, the DNA haplogroup Z16294 shows the connection to the other Nankivells, Tippet and other names in the group.
Further SNIP testing by a German company arranged by Mark identified which line. That is which earlier family or son of Robert Nankivell's sons is the ancestor. There was Richard 1680-1740, Benjamin 1682-1759, Samuel abt 1684-? and Samson Nankivell 1686-1769. Mark Nankivell is the best person to answer further questions.
It would be great if all Nankivell men tested so that more families could confirm their research.