the erythrocyte phenotype Fy(a-b-): 68% in African Americans and 88-100% in African people (including more than 90% of West African people). This phenotype is exceedingly rare in Whites. Because the Duffy antigen is uncommon in those of Black African descent, the presence of this antigen has been used to detect genetic admixture. In a sample of unrelated African Americans (n = 235), Afro-Caribbeans (n = 90) and Colombians (n = 93), the frequency of the -46T (Duffy positive) allele was 21.7%, 12.2% and 74.7% respectively. Overall the frequencies of Fya and Fyb antigens in Whites are 66% and 83% respectively, in Asians 99% and 18.5% respectively and in blacks 10% and 23% respectively. The frequency of Fy3 is 100% Whites, 99.9% Asians and 32% Blacks. Phenotype frequencies are: Fy(a+b+): 49% Whites, 1% Blacks, 9% Chinese Fy(a-b+): 34% Whites, 22% Blacks, <1% Chinese Fy(a+b-): 17% Whites, 9% Blacks, 91% Chinese While a possible role in the protection of humans from malaria had been previously suggested, this was only confirmed clinically in 1976. Since then many surveys have been carried out to elucidate the prevalence of Duffy antigen alleles in different populations including: The mutation Ala100Thr (G -> A in the first codon position—base number 298) within the FY*B allele was thought to be purely a White genotype, but has since been described in Brazilians. However, the study's authors point out that the Brazilian population has arisen from intermarriage between Portuguese, Black Africans, and Indians, which accounts for the presence of this mutation in a few members of Brazil's non-White groups. Two of the three Afro-Brazilian test subjects that were found to have the mutation (out of a total of 25 Afro-Brazilians tested) were also related to one another, as one was a mother and the other her daughter. This antigen along with other blood group antigens was used to identify the Basque people as a genetically separate group. Its use in forensic science is under consideration. The Andaman and Nicobar Islands, part of India, were originally inhabited by 14 aboriginal tribes. Several of these have gone extinct. One surviving tribe—the Jarawas—live in three jungle areas of South Andaman and one jungle area in Middle Andaman. The area is endemic for malaria. The causative species is Plasmodium falciparum: there is no evidence for the presence of Plasmodium vivax. Blood grouping revealed an absence of both Fy(a) and Fy(b) antigens in two areas