The Khoe-San people are some of the most diverse (genetically) in the world. They have many novel variants in their genetics. In fact, African Tribes often have more novel genetics than most other groups that are limited by bottleneck events or descended more recently from a smaller group. You will find more diverse genetics between african tribes than you would between most other ethnic groups.

"Comparative studies of ethnically diverse human populations, particularly in Africa, are important for reconstructing human evolutionary history and for understanding the genetic basis of phenotypic adaptation and complex disease. African populations are characterized by greater levels of genetic diversity, extensive population substructure, and less linkage disequilibrium (LD) among loci compared to non-African populations."

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2953791/