CCR5Δ32 Allele Frequencies
When tests like the one we just saw were performed on people all over the world, the CCR5Δ32 allele was found at frequencies from 0 to 14%. (This is the frequency of the allele in the gene pool, not the frequency of EU individuals in the population.) Population geneticists noticed the geographical gradient of frequencies, and suggested a selection for the allele that operated primarily in regions where it is frequent.

Note that even though the frequency of the Δ32 allele is low in Africa, there are African populations with significant numbers of exposed uninfected people.

INSTRUCTIONS:
Click on the EUROPE link to see a theory about the high frequency in this area.
Click on the AFRICA link to see a theory about other HIV resistance mechanisms.