The summary of this study seems to be: the number of people who are predisposed to speed is low, and the number of people with a gene that blocks full development of speed is high, therefore evolution favours endurance running.
Is it just me, or does this seem like somewhat of a stretch? When the span of physical activities of our species is considered, the importance of combat and/or sport in various societies throughout history, and the role of speed in the success of these, it seems counter-intuitive to say that those who achieve greatly are being bred out.
It strikes me as being akin to saying that because physical beauty (in an extreme) is such a rare trait that we're evolving past it, or have left it behind. There's something off about using rarity of occurrance as the root of a theory -- if I'm reading this correctly.
Additionally, there's the notion of our own history to examine: the claim is that this shift away from speed and toward endurance -- if indeed such a shift has really occurred -- has happened only recently in human evolutionary history.
Yet when you look at the past couple thousand years of our history, for the most part travel became very limited once domestication of livestock and crops became commonplace. What need is there for long-distance endurance running when people make little to no use of that ability?
If such a need existed, it would be more valuable in pre-agricultural times when a nomadic lifestyle may have existed without the aid of horses or other riding and pack animals to depend upon. Yet even then hunting would be more favourable for those who are capable of generating greater speed and power, much like other predatory animals.