What the? Reviving a 7 year old thread? Alright then, I'll join in. It is an interesting read and always an interesting topic. I have some Fijian friends (though I'm caucasian) who are just built like tanks. The pacific islanders (who originate from Africa) are big guys, and it's most definitely genetic. Many of my friends haven't exercised a day in their life (why would you when you live on an island paradise?), but they have large muscular statures. They do tend to be more fat as well, but put them on an exercise regimen and they bulk up like mad. They always tell the joke that the reason the Fijians are so large is because they had to store lots of food all at once for their long canoe rides. Ha! While this is comical, it's probably historically true. Fijians, Samoans, and the Maoris probably spent lots of time traversing the oceans and so they had to store mass for energy. That's the genetic basis. There's also a cultural/social basis to stature as well. Spend some time amongst the Fijians and Samoans and you'll soon learn that they eat a ton of food, especially meat. They don't just reserve themselves to the lean cuts either. They eat the whole damn animal, guts, fat, skin, and all. This definitely contributes to their obesity, and this shows that there's always part nurture and part nature in this sort of debate. By the way, pacific islanders are some of the most pleasant people to be around so if you ever have the opportunity to make friends with a Fijian or Samoan, you should do it. They are generous and jolly people.
As for the slavery bits, this is most definitely true. The "selective breeding" if you will (not intended to be offensive in any way, but it was just that), occured for many generations, not just three or four. Not only did the weaker Africans die out during transport, but on the plantations the slave owners would selectively breed the largest males with the strongest females. It was wrong, and all that, but from a physical standpoint it has led to general musculature advances in the general African American population. Anyone who has ever had serious college coursework in evolutionary biology should know that you can make substantial genetic changes over the course of 100 years, even with mammals. So while slavery may have contributed to the ghetto presence that exists in communities all across the US, it did have some benefit to the descendants in that they are genetically prone to larger musculature and faster gains. Rest assured however it should be obvious that I am appalled with slavery and feel that it has done more harm than good. There; that's my input on this dead thread.