The only point in the article is that with the current mix of human populations allopatric speciation will be difficult. This only suggests that humans splitting into new, separate subspecies will be more difficult.
However, we have had other information posted on EvC showing that evolution of humans is faster than ever. This isn't speciation just a greater range of diversity in the one species that we are. It is only speciation that the article is suggesting may not happen so easily. That is not all of evolution.
Since there are other ways for speciation to occur it is not true that it can no longer happen.
The article is also wrong is saying that natural selection is no longer happening. It is just different now.
The article is ok really. Just too simplistic but the topic is too big to cover in a few pages.
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