Stewart Haplogroup R1b 37 Marker Relationship Tree
This is the first draft of a hypothetical Tree for R1b Stewarts based on tests with 37 markers.
Analyses indicate that there are two recognizable but separate groups of Stewarts, colored red and blue on the graph, and many unassigned Stewarts, colored yellow. Large dots represent more than one test with similar DNA signatures at 37 markers. Tests contained in such composite dots are indicated within each group below.
Composite dots contain (31854, WTFSW), (20794, CKX65), (TH82K, 4137), (N2376, FKEY5), (35684, 7M85W), (13262, FQ3Y2), (73032, J2JGS), (48909, MQBGY) The blue group is related to the Scots modal signature, also known as the Dalriada modal, or R1bSTR47Scots. Some genealogists believe that this was the DNA signature of the early Dalriadic kings of Scotland.
(94608, WSU4J), (95961, F68FR), (44765, 9QZNY), (7155, 5MBFA), (20291, P6K33), (4874, 6KGSM), (3214, AEGC9), (11102, AZ59A), (64547, M2VDK), (7107, UZEME), (8101, 21686, 6695Q, Q252M), (69506, 2WWJ9, RARU8), (5603, E7RU2), (4874, 6KGSM), (23583, HQBJN), (52840, 388CJ), (45113, 7UK3B)
The red group is much closer to the WAMH modal that represents one of the oldest known roots of the R1b tree. I believe that the red group may represent descendants from the ancient line of the Stewart High Stewards of Scotland, who can trace their lineage back to Flaald of Dol in Brittany who was born about 1046.
(7748, SP52H), (GDVDJ, N6Q3U), (18112, 3JMBA), (94023, NQ43R), (47041, S22HC), (72199, 2RTEX), (17094, 6WSAW), (32164, 42KKX), (61935, 4CM74), (37290, ZK44Z), (20289), 87570, 5QW4Y), (29276, K4JRA), (85506, CU395), (N4830, VTVKD), (74246, QT2GR), (60467, EVNBZ), (87511, 4H9SS), (18929, VGR49), (6733, 103245, 5EEW4), (60417, R4AG7), (18260, 32347, 7CUVU)
The yellow dots are well separated from the other groups in terms of their Y-DNA, but this does not mean that these Stewarts are not related. It just means that they do not have an unbroken male-line linkage to the red or blue groups. Y-DNA measures pure paternal lines, not zig-zag cousin relationships, so male lines regularly "daughter out."
This is known to have happened within the senior lines of the Stewarts, the most obvious example being the Royal Stewart line of Scotland and England. Queen Elizabeth II descends directly from the Royal Stewarts via a number of different lines, but she has the typical zig-zag descent. The last direct-line male member of the senior (royal) Stewart line was King James V of Scotland. He had no legitimate sons and was succeeded by his daughter Mary Queen of Scots. Queen Elizabeth is a direct descendant of Mary of Scots, but only through combined male-female ancestry at several points. Most Stewarts can't boast such exalted parentage but the same principal applies to nearly all of us.
Membership of a Stewart clan was not necessarily based solely on male descent. The Clan Chief aimed at increasing his clan's power by arranging marriages to further his interests so the clan's family ties inevitably included many maternal cousins. So failure to prove descent through the purely paternal line measured by the Y-chromosome in no way implies that your line is not a "real" Stewart.
A name change could occur in Scotland when a man of property died leaving no male heirs. Frequently there would be a stipulation that a daughter could only inherit his property if her sons assumed her father's surname.
The situation might also arise in which both a Stewart daughter and her husband died, leaving orphans who were then raised and/or adopted by either her brother or father. Or half brothers were raised in the same household due to multiple marriages by the male, the female or both. In such cases the Y-DNA line may deviate from the surname.
Illegitimacy is another potential cause of a name change but in Scotland such children had inheritance rights which were much stronger than they would have been under English law, for instance. They might take their father's or their mother's surname but there need not have been any stigma attached. Scottish children who were born out of wedlock were legitimised if their parents later married and there was no bar to their marriage at the time of the birth. Even if that condition could not be met such children were frequently acknowledged and often lived with their paternal family.