Noted Olympic contrast

A sharp contrast is evident at the Olympic Games in London, almost all the sprinters are black and almost all the swimmers are white. The undeniable fact is that the ten fastest runners in the world are black and the ten fastest swimmers in the world are white. This is a fact, I am not a racist for simply pointing out this amazing difference.  In fact, even Britain, Holland, Germany and Norway were represented by Blacks sprinters, how many Blacks can there be in Norway?  One of my friends once characterized this as "our schvartzers against your schvartzers." Nevertheless, there must be a rational explanation for this distinction. 

I refer to a book called "Taboo: Why Black Athletes Dominate Sports And Why We're Afraid To Talk About It," that considers this question and thru research the author, Jon Entine, discovers that blacks descended from West Africa have more mitochondria in their muscle cells than Europeans.  This means that their muscles can carry out respiration, the conversion of oxygen into energy (in the form of ATP, the energy storage molecule in the cells) more efficiently and this allows them to produce more energy per unit time.  Hence they can run faster.  However, this is only a partial explanation, because while American Blacks and Caribbean Blacks hold all the world records in sprinting, and last night Jamaicans led by the great Usayn Bolt came one, two and three in the 200 m,  there are few West Africans who are such champion runners. So there is also a component of "nurture" rather than "nature" in this difference, namely the US and Caribbean Blacks live in countries that provide the facilities and have the culture that esteems fast running, so they also have the environment in which to develop their innate capabilities. 

Another legendary fact is that runners of certain countries dominate long distance running, namely Ethiopians, Kenyans and to some extent Algerians and other North Africans.  This has become routine in every major long-distance race, including the marathon and others at the London Olympics.  This has also been attributed to nature (inherent stamina) and nurture (long distance running from childhood).  But, there are two problems with the above explanation, people in East Africa do not appear to have a higher proportion of mitochondria than Europeans in their muscle cells.  Also the natives of the Andes in South America live at high altitude that has resulted in their having a higher proportion of mitochondria in their muscle cells to make up for the low atmopsheric pressure, and yet they are not known to be fast runners.  Finally, the explanation for the swimming contrast is that northern Europeans have inherantly long arms and legs and great flexibility and this allows them to swim faster than Blacks, and also there is the cultural factor, that Europeans swim much more than Blacks (the number of pools etc.).