Greg,
the oldest paternal line (biological father of the father of the father etc.) information is best obtained by following up your genealogical tree with your Father to his Father, then to the next Father, and so on until a 'last Father person' is reached. This person is also called most distant known ancestor in the paternal line.
mine appear to be...
1. Marvin Loyd Welborn b. February 10, 1949, Mansfield, De Soto Parish, Louisiana, United States
2. Henry Marvin Welborn b. July 6, 1922, Pelican, De Soto Parish, Louisiana, United States; d. May 28, 1999, Shreveport, Caddo Parish, Louisiana, United States
3. Henry Marvin Welborn, Sr. b. October 24, 1886, Soso, Jones County, Mississippi, United States; d. November 7, 1968, Mansfield, De Soto Parish, Louisiana, United States
4. Calhoun H. Welborn b. May 9, 1856, Soso, Jones County, Mississippi, United States; d. February 26, 1915, Pelican, De Soto Parish, Louisiana, United States
5. Younger Welborn b. circa 1824, Anderson County, South Carolina, United States; d. before 1900, Jasper County, Mississippi, United States
6. William "Billy" Welborn b. circa 1805, Pendleton District, Anderson, Anderson County, South Carolina, United States; d. circa 1880, Soso, Jones, Mississippi, United States
7. Aaron Welborne b. October 13, 1760, Rowan County, Province of North Carolina; d. October 6, 1843, Anderson District, South Carolina, United States
8. James Welborn b. August 18, 1736, St. George's Parish, Baltimore County, Province of Maryland; d. August 11, 1811, Barren County, Kentucky, United States
9. William Welborn b. January 21, 1713, Baltimore County, Province of Maryland; d. April 7, 1782, Rowan County, North Carolina, United States
10. Edward Welborn b. August 20, 1682, Caenby, Lincolnshire, England, United Kingdom; d. June 24, 1731, Baltimore, Maryland, United States
For the member whom asked about which ancestor.
if one is talking about the Y chromosome (was this thread not about R-M269 ?) and relative haplogroup the oldest known ancestor would be the oldest recorded male in the line of your records. Which assuming that there was never any deviation from that line ( adoptions, births out of the wedlock, single mothers...) is also a person whom shares all the characteristics of your Y chromosome.
Relationship to me
James Watson (1657 - )
10th great-grandfather
James Watt or Watson (1630 - )
Son of James Watson
Charles WattWatson (1652 - 1719)
Son of James Watt or Watson
George Watson (1678 - 1720)
Son of Charles WattWatson
Joseph Watson (1705 - )
Son of George Watson
John Watson (1740 - 1810)
Son of Joseph Watson
Evan Thomas Watson (1759 - 1834)
Son of John Watson
W. James Watson (1785 - 1865)
Son of Evan Thomas Watson
John B. Watson (1824 - 1890)
Son of W. James Watson
Elam Columbus Watson (1856 - 1923)
Son of John B. Watson
Warner M. Watson (1901 - 1968)
Son of Elam Columbus Watson
Jessie Loyd Watson (1939 - 1993)
Son of Warner M. Watson
Dana Lea Watson
You are the daughter of Jessie Loyd Watson
well, since 50% of western European males are R-M269 we are all related along the paternal father’s line. Which is not quite as saying that we are all family but to some extent it shows how limited the gene pool was when our line (a very successful one, obviously being so widespread and numerous ).
Until now, despite me belonging to this huge haplogroup, my Y-37 ( that’s why I am reluctant to carry out the very expensive “ Big Y”) has yielded very few results and only at 12 mutations level.
Just to put these things regarding our oldest known ancestor into a perspective (even if limiting it the Y chromosome haplogroup R-M269 which is, as we said, the most common group among the European males) take a look at this Stephen Fry talk.
https://www.youtube.com/watch?v=MganV8ikNHc&frags=pl%2Cwn.
After the ice age there were so very few people around that one male (whom we will never know), became our oldest ancestor and we number now in hundreds of millions. Still it is nice to know, while sitting in a bus or train in Western Europe . That 50% of the males sitting there are related to us along the Y chrosome, and if we consider both chromosomes we are probably bringing this up to almost 100% of all the people in there!
Everything is relative and needs to be taken with a rock of salt.