Really? Seriously? Then why isn't distance running completely dominated by Asians? They should be crushing everyone else if that is the case.
The first two big red flags for doping are:
1. An athlete comes out of nowhere to set a world record, usually in a race that conveniently does not drug test except for the day of the race. The performance is rarely or in some cases never repeated.
2. The athlete is a female, and the program (nation, team, coach, etc) never produces a male athlete who is even remotely elite. (If the training program is the main reason for success, it should work just as well for men as for women.)
Using those two criteria explains why most (probably not all) of the African distance runners are clean, most of the American swimmers (probably not all) are clean, and all the Chinese women who set these "world records" (as well as the East German female swimmers from the 1970's and 1980's) are dirty.