Following the complexities of Y-DNA can, at times, be a daunting task. There are scientists and hobbyists that thankfully allow the rest of us to observe in awe of what they understand. Dr. Ken Nortdvedt is a professor emeritus in the Physics Department at Montana State University. He is also an active genetic genealogist, and has also done his own research into genetic Haplogroup, particularly the Y DNA group I to which he belongs, and advises on haplotypes for a population genetics group at FamilyTreeDNA. Nordtvedt has proposed a new most recent common ancestor calculation method.
Our family belongs to Haplogroup I where it is a member of a rare subclade known as L369 or "Isles-Scot". Dr. Nordtvedt constantly updates a particular graph on his site that provides the downstream markers for the M223 subclade. The M223 subclade is upstream from our L369, meaning our Y-DNA was once part of a larger subclade (M223) before its present day signature (L369) was derived. After M223, and before our L369 subclade, our Y-DNA modified into the M284 subclade. The M223 subclade occurs in Britain and northwest continental Europe, while the M284 subclade occurs almost exclusively in Britain, so it apparantly originated there and has been present for thousands of years. Our L369 subclade is downstream of M223 and M284. L369 (aka Isles-Scot) is not only believed to have originated on the British Isles, it is primarily found in Scotland. These subclades are derived by a single nucleotide polymorphism (SNP). These unique SNPs are given a nomeclature (M223, M284, L369, etc.) and allow Y-DNA scientists the ability to seperate out the individual branches of the larger Haplogroup.
By looking at Dr. Nordtvedt's chart, you will begin with M223 on the left and follow the line up to M284 and then up once again to the area marked as "L126 L137 L369" and also "Isles-Scot". This is our family subclade branch. We are positive for L126/L137 in our Y-DNA and by also showing positive results for L369, we seperate ourselves from the "Limbo" subclade who are only positive for the first two and not L369, and are labeled as "Isles-Scot".
You can see by the timeline on the bottom of the chart, the period of time that Dr. Nordtvedt believes these various subclades or branches were formed from their orignator. Based on the results of 2 Oct 2012, this puts our ancestors on the British Isles, and primarily in Scotland, as early as 5,500 years ago and on the British Isles as late as 8,500 years ago or longer.
Who were the originators or progenitors of the M223, M284, L126/L137, and L369 subclades? At this time, there hasn't been enough evidence to point to any particular male. A generation is calculated at about 30 years. Historical information of the British Isles becomes a little distorted the further back you go. Some would even say that fiction has entered into these historical documents as it was passed down. I've written about these records and that our surname is included with the great kings of the British Isles. Hopefully, one day we'll be able to determine who the progenitor of L369 was. By continuing to look for unique SNPs and testing for them, we are getting a little closer.
You can also find the entire Haplogroup I tree on Dr. Nordtvedt's site where you'll see a dotted line box of the M223+ on his chart and then navigate to the left to continue going further back in time. You can also access the International Society of Genetic Genealogy (ISOGG) where this haplogroup tree is displayed.
William and Annester Gowin of Lunenburg County and Bedford County, Virginia
