Genomics For Fun

Diabetes and increased BMI are positively correlated with major depression in Western societies, but negatively so in Eastern societies (Taiwan). Breast cancer (Japan) and schizophrenia (China) are correlated almost identically with Western norms from GWAS studies. This may be because depression is more  multidetermined, so cultural factors such as nutrition, smoking, ideas of attractiveness, and alcohol matter more in depression, while factors that go back tens or even hundreds of thousands of years matter more in the cancer and schizophrenia.  In all three cases, this is because of hundreds or thousands of genes increasing or decreasing risk 0.1% or 1.1%. 

This is a wonderful opportunity to make up your own story about the positive and negative correlations in depression, though. Because at the moment, you can't be wrong. The major researchers also have narrative speculations, but admit they are just guessing. Just be prepared to find out that your brilliant idea turns out to not be right.

Also fun. The Netherlands is a small country, about the size of NH and VT put together, but its genetic heritage turns out to be sharply (by European standards) divided between north and south. The Rhine was the frontier for the Roman Empire, and when the Spanish controlled the Netherlands most of the movement into that area was confined to the lower part. In fact, there is lots of southern European blood in southern Netherlands, not so much in northern. More people with brown rather than blue eyes, for example, even today. However, it seems that this natural division existed back well before the Spanish and even the Romans. The Dutch have divided north and south, at least in terms of who married whom, even before that, perhaps even twice as far back. (Hence the eye color.) This does get messy, because people in coastal areas often have wider connections, and in Holland, pretty much everyone is in a coastal area. My wife's mother was from Bergen op Zoom, for example, which would suggest that she was more closely tied to not only Belgium and France, a stone's throw away, but to Italian, Southern French, and Iberian heritage. Except the DNA breakdown is much more strongly Scandinavian and Northern European. The fact that the next generations back were largely from Rotterdam and surrounding, just above the Rhine, turns out to be a big deal. She was northern Dutch, which is a real thing for centuries.