Body proportion and height is a completely different thing. The pygmys who live in deep forest area that average about 4'5" in height also have tropical body proportion. Meaning their legs are disproportionately longer than their torso. Have you ever heard the term that black people have a lower sitting height than other non-Africans?
Honestly where are you getting this from?
People of African decent tend to have a higher risk of miscarriages since their torso is shorter than other non-Africans their birth canal are shorter so it becomes difficulty to give birth to large babies.
No evidence to support you claim, however...http://oehha.ca.gov/...ffic120809.htmlhttp://www.fetalmedi...miscarriage.pdf
Also, African-Americans originate in western Africa(Ivory Coast region). They're the same people you see in the NFL/NBA/Soccer/etc. They don't average no damn 5'7. But I do agree that the Dinka of South Sudan and other tribes in the horn of africa do tend to be tall.
Yes the Ivory Coast was a major hub port for the African Slave Trade. However, only a small portion of the men and women sold into slavery were actually from the coastal region. The majority of people sold into slavery were captured closer to the central regions of Africa. The slave traders could not get into Africa in sufficient numbers to take over militaristically by using the coast and they could not do so across the desert. So, missionaries began to spread and interact with local tribes teaching them European languages. Afterwords, technologies such as guns were introduced to certain ethnic groups that were receptive to trading with the Europeans. Through encouragement, bribery and trade, they began to draw lines of division among the different ethnic groups, sparking wars and breeding hate amongst groups that had lived together peacefully for centuries. The losers, regardless of any previous trade agreement with the Europeans were often sold into slavery. This lack of concern for previous ties or treaties meant that many different ethnic groups in Africa became slaves. The remaining Africans lost many of the original geographic boundaries that separated them from each other, making the subsequent colonization from Europe possible.
This is how the history of the slave trade is taught throughout Europe and Africa and most of the developed countries I have been to.