What makes you think this? I live in Europe and Scandinavians are very similar in build to other Europeans. I get the impression your not a European. Maori's have a large body mass, like many Polynesian people. They all do rather well at rugby. But Lithuanians? There are many living in London, and again they share a similar physique with other Europeans. Exceptions only prove the rule. It's my theory that these people dominate the resource rich areas of central and west Africa because they beat other racial types in conflict (including the east African type that you referred to). It's really the development of weapons which has given us the edge over them. Possibly. But since there is a greater genetic variation between Africans than all other races, it's hard to see why the inclusion of any other race in a breeding program would be necessary.