Those pages talk about self-segregation, which is not something you can realistically blame on any group. Every group does this.
Frankly I find this pretty weak. If you want offensive pieces of known science relating to race, why not go with Darwin's "island species", which basically says that there are 2 ways evolution can go:
1) there are barriers (artificial or not) between races. At this point races slowly evolve into species (at which point they fully diverge). Racism is theorized to be one such barrier.
You might think the above is a bad situation ... until you think about the only alternative.
2) There are no barriers between races. At this point races are a temporary phenomenon : all but one race will die out. Now you might think that if you put 2 races of animal together the surviving group will be a mixed form, however that appears not to be the case. The result of mixing 2 races, is that one only a single race survives.
The reason is simple. Take "most blacks" genetic makeup in the united states. There was a period where people preferentially had kids with white people. This has resulted in that the large majority of african americans have a number of generations which were mixed-black + white person in their ancestry, increasing the ratio of white:african genes. The problem is what happens in a couple where a mixed + white marriage is in both parents' ancestry. When 2 second-generation mixed black marry, the odds are very good that the child will have more indo-european genes and less african ones than either of their parents. This is already plainly visible on the street in the US, if you've been to Africa. Most african americans lack several typical black characteristics (large lips, large color change between front and back of the hand, and the individual hairs on the skin are much thicker, but there are less of them) and in more internal characteristics (for instance there is barely any difference between african americans and whites in lactose intolerance anymore, whereas in Africa it's easy to find regions with 80%+ of people lactose intolerant). It is no longer unheard of for 2 african-american parents to have a child that is white (in phenotype), and it's about to become the norm.
Now while it's true that the advantage of one set of genes was generated somewhat artificially for this group, the theory says that there will always be some reason that one group's offspring will outnumber the other group (same argument as for natural selection, really), and this will always happen. Whether it be because of social preferences or some other property doesn't really matter.