Says the Times: "The graphic records two sets of correlations (labelled PC1 and PC2) in the genetic data derived from the various populations." Can I say what that means, exactly? I cannot. But the key takeaway here is that the proximity of any two points on the chart correlate to genetic similarity between individuals. And as you can see from the color-coding, individuals from the same country clearly cluster genetically. There is, though, a fair bit of overlap, except when it comes to the ever-anomalous Finns, who appear to have wandered off the genetic reservation altogether. Indeed, the Finns appear to be suffering the peculiar existential condition of not even being all that genetically similar to themselves. (CEU refers to the general European population, by the way.)
The researchers have drawn some interesting conclusions from their study.
The Australian team says that natural selection has probably helped differentiate the various populations in their survey. Another factor may be that the Irish have inherited more genes from the first settlers of Europe, hunters and gatherers who were followed by people who practiced agriculture, while the Finns may have some ancestors who came from East Asia.It would be interesting to discover that the Irish have evolved to inhabit a uniquely Irish niche in the ecology of Northern Europe, and the Swedes another distinct niche, etc. That would seem to be to me the consequence of what these researchers say, and I find it surprising; I always figured whatever genetic differences existed between populations were just due to genetic drift. But of course, whatever differences we're talking about aren't very large, anyway. It's not like we're talking about different species or anything.
On the other hand, if you cock your head and look at a Finn in just the right light...