Interpretation of Landry yDNA Results
All of the Landry cohort fall into the haplogroup R1b1a2 now called R-M269. This group has its origins in central Asia followed by migration to Europe. The Guillaume Landry descendants were a subgroup previously denoted by R1b1a2a1a2c and now named R-L21. The Jean Jacques descendant was in another subgroup originally called R1b1a2a1a1a and now named R-U106. The highest concentration of these haplogroups in the current population is in Western Europe including the British Isles. For more information about haplogroup classification and maps showing distribution go to: http://en.wikipedia.org/wiki/Haplogroup_R1b_%28Y-DNA%29 .
The yDNA results have shown clear patterns of three family groups. The Acadian lineage includes descendants of Rene le jeune Landry and Rene l'aine Landry. Descendants of Guilluame Landry form the second group. The lone descendant of Jean Jacques Landry line forms the third group. There may be other Landry lines but their numbers probably are relatively small and no one associated with them is included in the database.
The similarities among descendants of Rene le jeune Landry and Rene l'aine Landry show that they are related. Within this Acadian group there are clear differences on the markers DYS389 I (14 vs 15) & DYS389 II (30 vs 31) between descendants of Rene le jeune Landry and Rene l'aine Landry, respectively. Since these differences show up in all of the respective descendants to date, this mutation probably occurred at one of the Rene's births or in an earlier generation before one of their births. According to Terry Barton, these markers mutate together, so these differences represent one mutational event. (1) Stephen White through analyses of Catholic Church Dispensations showed that their common ancestor was not their father or grandfather. (2) That would put the birth of their common ancestor at or prior to about 1565. Since the two Renes immigrated from France, it is logical to surmise that this ancestor probably was born in France as well.
Rene le jeune Landry had eight sons. We have yDNA samples from descendants of five sons: Antoine, Abraham, Germain, Claude, and Pierre. We do not have descendants from the other three sons: Jean, Rene, and Charles.
Within the Rene le jeune Landry line there are several interesting relationships. Two individuals (#18198 and #23538) are second cousins and differ on one marker, DYS CDY, so the mutation must have occurred within the last three generations. Since #23538 has the same value for DYS CDY as other members of this group, this mutation must have occurred in the line represented by #18198 (WPL, BRL, or BRL.)
Two other members (#114234 and #81856) of the Rene le jeune Landry group have a common single mutation at DYS CDY. Therefore they must have a common ancestor more recent than Rene le jeune Landry. Member #114234 whose lineage is private, descended through Rene's son, Claude and grandson, Claude. Therefore member #81856 should explore connections in this line. I can help with this search if given more details of his recent ancestors.
Two members (#212444 and #405029) of the Rene le jeune Landry line share the same lineage through six generations (Rene le jeune, Antoine, Antoine, Alexis, Amand, and Jean Baptiste) and have exactly the same yDNA profile.
Three members (#145199, #212444, and #405029) of the Rene le jeune Landry line have known pedigrees that pass through Rene's son, Antoine Landry. Then the lineages split with #145199 passing through Antoine's son, Jean, and #212444 and #405029 passing through son, Antoine. There is a single difference in their yDNA profiles at DYS442 which probably represents a mutation in the line to #145199.
Two other members (#255067 and #264308) of the Rene le jeune Landry line have known pedigrees that pass through Rene's son, Abraham. Then the lineages split with #255067 passing through Abraham's son, Rene, and #264308 passing through Abraham's son, Abraham. There is a single difference in their yDNA profiles at DYS458 which probably represents a mutation in the line to #264308
Four members of the Rene le jeune Landry Group (#212444, 255067, #23538, and #405029) and one member of the Rene l'aine Landry Group (#27044) showed no deviations from the mode values. In addition, the profile of #27044 was the same as the mode for the Rene le jeune Landry Group except for DYS# 389 I & II characteristic of the Rene l'aine Landry Group. These yDNA profiles probably are the same as their respective progenitors.
The rate of mutation is calculated as the actual number of mutational events for the cohort group divided by the product of the total number of birth events from the appropriate progenitor to each descendant times the number of yDNA markers. As of June 29, 2013, the number of mutations within the Rene le jeune Landry line is ten, the estimated number of birth events is about 100, and there are 37 markers = 10/(100*37) = 0.0027. This rate is slightly more than the FTDNA average of 0.002.
1. Personal communication from Terry Barton (web master of worldfamilies.net).
2. White, Stephen A., English Supplement to the Dictionnaire Genealogique des Families Acadienes. Centr d'Etudes Acadienes, Universite de Moncton, Moncton, NB, Canada, pp. 194-5.