you guys are all talking out of your asses. first off, evolution takes millions of years. and the main reason that blacks can run faster and jump higher is not because of there physiques, because if that were the case, there would be some white guys (white guys can have excellent physiques, not as commonly, but they can...ie me) in the 100 m dash in the olympics, but there never is. if you've ever actually read about studies on african physiology, it has shown that blacks have, on average, more collagen in there tendons. therefore, whenever they run, jump etc, more energy is conserved in elasticity, and can be put back into the next jump, or step. why do blacks excell in long distance (kenyans etc): same reason, but there is also another advantage of the african physique, they are thinner. due to millions of years in subsaharan africa, blacks have developed superior heat regulatory systems. firstly, they have longer appendages (look at most black guys, they are taller, have smaller wastes, thinner longer fingers, longer feet, and toes, thinner ankles, etc.), this enables them to radiate heat faster (surface area/volume ratio is much higher). and heat loss is the primary concern of any long distance athlete. (studies have shown that when equivalent masses of rats and humans are compared, the rats can produce 9 times the power of the human-this is due to heat loss, their surface area of all the rats combined is much much higher than that of the human with the equivalent mass to all the rats). also the black skin helps, black is the most emissive color when it comes to radiation, yet another reason why they can keep cooler. also, studies have shown in biopsies of blacks that they have more blood perfusion per muscle fiber (more capillaries/muscle fiber), which enables them to transport more oxygen to the muscle under aerobic conditions, effectively allowing them to produce more energy with out lactic acid breakdown. as far as being bigger, that is a fallacy. they have lower body fats so that there is less insulation = more heat loss). as you can see, almost all of the traits that blacks have the make them superior in most sports are derived from heat regulatory systems. i could write more, but the gym is calling me. later
-beefy