But, be careful where you point fingers now. This stuff can get really, really touchy real quick. And, much of what some of us would think on first glance ain't exactly true. That is part of why there are no published papers on the issue.
In truth, some physiologists cannot help but see physical differences in races and sub-races of people. In one instance, I can almost always tell the "race" (country of origin) of three different types of people simply by their heart catherization (of which I have seen hundreds) film. The point is, different people are different.
Yet, in the scheme of things, they are still "Us." Some of "us," however, have greatly different aggravation levels than others of us. The above article hints to some of that. We see other problems domestically.
We had a thread recently which touched on this touchy subject. Gene Study Identifies 5 Main Human Populations . Check out post 42.