Why Do African Populations Have More Genetic Diversity Than Populations

Why do African populations have more genetic diversity than populations elsewhere in the world?

A) African populations experience genetic mutations at a higher rate than other populations.
B) African populations have nuclear DNA that undergoes recombination at a higher rate than other populations.
C) African populations were isolated from other populations for tens of thousands of years.
D) African populations are older than other populations and have had more time to accumulate mutations.
E) African populations have mtDNA that is more susceptible to mutations compared to other populations.