Untangling a murky DNA mystery

My late grandmother was always dubious about the pursuit of genealogy - she warned me more than once that I should let sleeping dogs lie, and not dig too deep (I suspect I inherited my fondness for mixing metaphors from her). Ironically, when it came down to it, it wasn't her side of the family tree that turned out to be shrouded in mystery, but another.

Last year, at the urging of various parties, I signed up to be tested as part of the Buchanan Y-DNA Project. We were determined, once and for all, to nail the Drumquin Buchanans down. More fool us.

To cut a long story short, a couple of distant cousins tested before me, and tested positive for what is known as the chiefly line of Clan Buchanan - that is to say, their DNA samples matched, in particular areas, those of other lines with proven descents from the Clan Chiefs. Simple enough so far? Ok, so a descendent of Alexander Buchanan, eldest brother of my great grandfather, Robert Hamilton Buchanan, tested positive in that regard. Another likely cousin from the Kirlish branch of the family, based a stone's throw down the road, also tested positive. those tests were undertaken a few years back, however, and with new procedures available to tests SNPs (no, not Scottish National Party members, rather single-nucleotide polymorphisms), everyone involved was keen to have me test, in the hope that it would offer new data. And boy, oh boy, did it offer that.

First off, I tested for A1094. It sounded to me like a country road, minus a border crossing, but is basically one of the key strands that you look for the in the Buchanan chiefly line. And it came back negative.

Now that, in and of itself, wasn't a knock-out blow. It just meant that we weren't as related as we thought we might have been to some of the neighbouring Buchanan families in Omagh, Donegal and the like. That was a little surprising, but not outwith the bounds of possibility. So I submitted a second test, this time for fgc32575. The codes were losing me by this point, but Ross, my inside contact, explained that pretty much all Buchanan male line DNA would test positive for that, and then we'd narrow it down from there to see where we fitted within the broader family tree. Only we didn't. That test came back negative as well.

Now that was something of a knock-out blow, if I'm honest about it.

The DNA evidence, albeit from two very specific tests, was clearly saying that I wasn't a Buchanan at all. How could that even be possible?

Well, there were four possibilities, when I looked at it clinically.

Given that we knew that Alexander's descendents had tested positive, and I had tested negative, there had to be a break at one of four points in the recent family tree. Either my great-grandfather wasn't who we thought he was, my grandfather wasn't who we thought he was, my father wasn't who we thought he was, or I wasn't who we thought I was.

That last option led to a very interesting Skype conversation with my mother, who could barely control herself through the tears of laughter as I asked, ever so subtly, if there was anything she needed to tell me before I dug any further. Thankfully, between the tears and chortles, she assured me that there wasn't.

The other three options might have been harder to pin down if it hadn't been for the help of another cousin. The son of one of my father's first cousins offered to take the same couple of tests that I'd taken. If his results differed from mine, then I'd have to face some unconfirmtable possibilities. If they matched mine, then we knew that his father and my father had to be a match, just as our two grandfathers had to match. That meant the break had to be at the earliest possible point, with my great-grandfather. And, as it happened, that's what eventuated. Our two sets of results were identical, which led to the simple conclusion that, somehow, Alexander and Robert were not, as we had always assumed, brothers.

I've been pondering this for a little more than six months now, The first couple of DNA tests were so specific that they didn't cost a great deal. The only possibility now open to us, given the break in the line, was a larger Y-DNA test, which was considerably more expensive. What with Christmas, and a few other committments, I put it off for a while, and pondered less scientific explanations instead.

Looking at the dates of those involved, it was pretty obvious that my great greandfather, as one of the youngest of eleven supposed siblings, might well have been born to another mother and then quietly adopted by the people I had always presumed were my great-great-grandparents, John Buchanan and Sarah Jane Condy. Indeed, he had two sisters old enough to have been his biological mother. One of those later married, and had children of her own. The other, the eldest, disappeared without a trace a few years after his birth - she appears in the 1901 Census, but is gone by the 1911, and there are no obvious records of where she ends up, no shipping papers to suggest that she emigrated, no marriage records to account for a change of name, and no sign of her in either Dublin or Scotland, where scraps of family lore hinted she might have headed. For that reason alone, I began to wonder if she might, in fact, have been Robert's mother, and if the couple I had long supposed to be my great-great-grandparents might, in fact, have been my maternal great-great-great-grandparents, who took the child in, and raised him as their own. That raised a whole series of other questions, of course. Were his two younger siblings similarly fostered, or were John and Sarah still raising their own family at the time? And if Margaret,. their eldest daughter, was in fact Robert's mother, who was his father?

So, six months or more on, I have now taken the next leap, and have ordered what is colloqually called a Big Y - a large scale Y-DNA test which will focus on my paternal ancestry, and will hopefully help me to pin down some close matches at the fifth or sixth generation that can shed light on the missing man in my life.

Some friends and cousins have asked, and others will doubtless be wondering, why I haven't gone with the Ancestry.Com option, and it's simply that I've been advised that, since we're looking for a break in the male line, and we think we know where that is likely to have occurred, it makes sense to focus on the Y-DNA at this stage. Ancestry's DNA tests are both patrilinier and matriliner, and as such might give us a broader spectrum of results, but we might then be hard pressed to distinguish the two strands one from the other. I'm not ruling out taking their test at some point in the future, particularly if there are still unanswered questions, but for now, Big-Y seems to be the way to go. As a result, I've ordered the Y-111 (which looks at 111 short tandem repeats on the Y chromosome), as offered by Family Tree DNA, who have been handling the Big Y project for the Buchanan Clan.

I'll let you know what results we turn up. Hopefully it sheds some light, rather than revealing more murky questions, but I guess only time will tell.

I do know this though - there's a good deal more wisdom to be found in a grandmother's advice than many a grandson will willingly admit! Still, they do say every dog will have his day ...