Using the Harris-Kalmus sorting technique, PTC tasting data were collected in Libya and Kenya. The three Libyan regional samples were homogenous, though collectively markedly different from the Kenyan series. The Kamba group in Kenya was notably different from the other Kenyan groups. Overall, the data partly establish and partly corroborate the existence of a gradation in PTC non-tasting frequencies from very low values in Negro Africa to somewhat higher values in Hamitic Ethiopia and to very much higher values in Libya. The data at present available are insufficient to permit a detailed description of geographical variability in African populations.
Sunderland, E and Rosa, P J.
"The Ability to Taste Phenylthiocarbamide among the Tripolitanians, Cyrenaicans, and Fezzanites of Libya and the Kikuyu, Kamba, and Taita of Kenya,"
4, Article 7.
Available at: https://digitalcommons.wayne.edu/humbiol/vol47/iss4/7