This is related to the Out of Africa theory Long story short, as you move out of Africa, you'll see larger genetic differences within Africans than between Europeans and Asians.
The worldwide pattern of single nucleotide polymorphism (SNP) variation is of great interest to human geneticists, population geneticists, and evolutionists, but remains incompletely understood. We studied the pattern in noncoding regions, because ...
pmc.ncbi.nlm.nih.gov
Take lactose intolerance for example. Lactose tolerance is uncommon in Humans, after a certain age. However Europeans are almost always lactose tolerant, no matter the difference between the countries you compare. Then we look a African, lactose tolerance rates significantly more inconsistent....most Africans are lactose intolerant and some groups are more tolerant than Europeans. And these African groups are separated by 1000 miles like Europeans are.
Why are some populations able to digest dairy more easily than others? In this text, we explore lactase persistence (the...
www.labxchange.org
Put it all together. FBA has, genetically, less in common with most of African because of our proximity to Europeans.
We're inherently more European than someone from the Zulu, not by much though. Its not a good or bad thing. It just is.