Apollo
VIP
How does your 90 % claim square with the fact that the paper concludes that " the majority of populations of East Africa have lactase persistence at moderate frequency. "
Database is skewed by Nilotes who have it at a lower frequency. The Beja are at 88%.
The frequency of lactase persistence was highest in the Afro-Asiatic–speaking Beja pastoralist population from Sudan (88%) and lowest in the Khoisian-speaking Sandawe hunter-gatherer population from Tanzania (26%) (Fig. 2a and Supplementary Table 1).
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2672153/

Puntlanders will have higher numbers than Bejas..