The DNA we carry contains a myriad of stories. One of the most fascinating is the journey of migration that our ancestors took after they left Africa. I’m one of about half a million worldwide who have participated in the Genographic project, run by the National Geographic magazine, which is aimed at elucidating these stories. The results from my DNA arrived last week… and that’s where the inner Neanderthal is revealed.
I should first explain how I got interested in this. It started because my Dad was fascinated by the history of the Tweedy family: he was very proud of the fact that the Tweedy family line originates in lowland Scotland (around the banks of the River Tweed), and can be dated back to the 13th century – for example, to Fynlaw de Twydyn in 1296, “del Comte de Lanarke”. Our immediate ancestors settled in Cornwall around Truro in about 1800, but their connection with the older generations was obscure. This story might therefore be clarified by analysis of the Y-chromosome, which – being passed solely down the male line – tracks the inheritance of surnames.
About two-thirds of male Brits carry Y chromosomes that belong to a group known as R1b. As this proportion rises to about 80% in Cornwall and 95% in Wales, it is tempting to regard it as being related in some way to the Celts, but there’s a danger in oversimplifying a story which is actually woven into the ancestry of most western European males. The migration history of this group, which started in Africa, has been traced through west Asia (east of the Urals; possibly around 18,000 years ago) and then, after the last Ice Age, from there into much of western Europe.
I had discovered from an earlier foray into DNA analysis that I actually belong to a completely different and rather small genetic group. As part of the I2a group, my distant paternal ancestors left Africa along a shorter route via the Balkans – for reasons probably related to the climate at the time – arriving there possibly 12,000 years ago. They then ended up predominantly in Germanic and Scandinavian countries (that is, Viking and Anglo-Saxon). However, they account for only 9% of males even there, and probably only a few percent at most in the UK.
Rather than helping to explain the ancestral Tweedy story, it obscures it. The only other Tweedys reported online belong to the R1b group. This suggests that the connection between the Tweedys of Cornwall and the lowland Scots is not as secure as I’d thought before. If so, my Dad – who was keen on his Celtic origins – would not be happy. Personally, I’d be content with Anglo-Saxon origins (think of St Cuthbert and King Alfred); but there is a glimmer of hope for the Scottish connection, as a remarkable number of I2a’s who’ve reported their ancestry on the Genographic website seem to have Scottish origins.
The Y chromosome data is, in some ways, deceptively straightforward, as it follows an exclusively paternal line. The rest of the DNA is a complex blend of both paternal and maternal lines. For most people, wherever they live, this reveals a variety of geographic origins, and in western Europe this is usually a combination of Mediterranean, Northern European and South West Asian. As it happens my particular mix is fairly similar to most Brits – but, curiously, it is closer to the German average. Perhaps there may indeed be Anglo-Saxon roots!
It’s this last bit of analysis that connects me with the Neanderthals. Apparently, my DNA is about 2.1% Neanderthal… which actually makes it typical of most Europeans. It has to be said that I’m not entirely sure how solid the science is behind this measurement. The hypothesis on the Genographic project is that the Neanderthals died out because they interbred with incoming Homo sapiens – which is a nicer story than the more conventional one, that they were either out-smarted or out-fought – but I remain slightly sceptical.
A second motivation behind this investigation is more faith-related. I’m theologically conservative on most things, but I think that evolution is the technique that God used to create. Hence I am excited by the stories revealed by evolutionary science – but they do nothing to diminish the reality of a Creator God.
My faith also gives me a different perspective about what the data reveals about our identity. One of the headings on the Genographic results page is “Who am I?”, to which their answer is the geographic origins of the DNA – and the Neanderthal component! This would seem to be somewhat absurd, even without assuming a faith perspective. Much as I am fascinated by the DNA story, I believe ‘Who am I?’ is much better answered from a spiritual standpoint.
Bird pix of the week
Let me finish this post with a couple of bird pix (because I like an excuse to share them). The first is of a pintail at Slimbridge last week: the lighting was just right, not least for showing the iridescent copper patch on the back of its head. Later in the afternoon I went to Pittville Park in Cheltenham to see the Great Northern Diver that had dropped in for a few days. Although they are a fairly frequent sight around the coast in winter, they are unusual inland, let alone in a town park!