While it is true that the septs within CJU have a detailed genealogical record, there is another as interesting aspect: the genetic history of the Ulster-Scot Joyces. What if we told you that all males who directly descend from the Joyce/Joss family of Ulster inherited a very specific stand of Y-DNA? Furthermore, what if we insisted that each sept has their own specific mutations only associated with them? The truth of the matter is that thanks to advances in genetic genealogy, this is the case. And as you can imagine, this leads to an interesting question: what have these discoveries led to, and how has it changed the research methodology of Clan Joyce of Ulster?
From a practical viewpoint, the information gathered from Y-DNA results have had important implications. Ever since the Joyces emigrated from Ulster their ancient Scottish origins had all but been forgotten. However, this is not surprising when you consider the Joss family settled in Ulster, Ireland around the year 1702 CE. Then in 2015 two Joyce males submitted their Y-DNA to be studied by Family Tree DNA. Fast forward to the year 2022 and there are a total 17 different Joyce males who have had their Y-DNA studied at the highest levels. Originally only one Joyce lineage had their DNA tested, but now all three major septs are present. This even includes four kits that represent Joss males who can trace their lineage back to Banff, Scotland. Needless to say, without their Y-DNA all these test takers would not even know they had Scottish origins. As a consequence, Clan Joyce of Ulster now considers Y-DNA crucial to the study of the Joyces from Ulster.
By definition Y-DNA is considered to be part of the Y-Chromosome which is found in men only. As a result, Y-DNA is passed from father to son to grandson etc., over the many hundreds of years. For those living male descendants of the Joyces from Ulster, they are born with a very specific line of Y-DNA. In particular, this strand of DNA goes back to the Joise family of Aberdeenshire, Scotland. What is more, however, is that each sept has certain mutations that was only passed down their line. In other words, a new mutation was born at the birth of a particular Joyce male. The follows graph highlights these markers:
Beginning with R-Y11201, all Ulster-Scot Joyce males have this mutation which has origins deep in Scottish history. It is unknown when this marker was born into existence, but it might have been sometime around 1580 CE. To this today, R-Y11201 is still being passed down to the direct male descendants of Thomas Joise (b.1609). And similar to R-Y11201, there are four other Y-DNA mutations that are more recent. R-FTB42619, for example, was born with Alexander Joyce (1720-1778) of Ballynahinch, County Down and is only inherited by his direct male heirs. For the Joyces of Ballydugan, County Armagh R-FTB53897 started with George Joyce (b. 1721) and is very specific to his sept. And finally, for the Joyces of Ballydonaghy, County Armagh, there is R-Y43252 and R-FTA92314. Because of these discoveries, it is no surprise that CJU now heavily depends on Y-DNA to confirm new septs and to expand its family tree. One could even say it has transformed how the clan performs its genealogical research.