Bitter Taste Perception Test (image) University of Pennsylvania Caption Researchers from the University of Pennsylvania asked 296 Africans from a variety of groups -- here, a group of Yaaku people in Kenya -- to perform "taste tests" of progressively more concentrated solutions of salicin and report when they could detect a bitter taste. They matched the participants' genotypes onto their phenotypes, and found one genetic variant, prevalent in East African people, correlated with a high sensitivity to salicin's bitterness. Credit University of Pennsylvania Usage Restrictions In context of reporting on study. Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.