GENETIC-VARIATION IN SRI-LANKA

A population genetic study was designed to analyze genetic composition and population structure of the five main population groups (Sinhales e, Tamils, Moors, Burghers, and Malays) of Sri Lanka. Twenty-seven pol ymorphic and three monomorphic loci were examined in all five populati ons. Several genetic markers, including subtype variation of HP, TF, P I, GC, ORM, and PGM1, were analyzed for the first time and helped to c larify the range of genetic variation for Sri Lankan populations. Many genetic systems (Rh, JK, ACP, ESD, HP, C3, TF, and GC) showed a high level of variation among the populations of Sri Lanka. However, at the individual level the Burgher population (a hybrid group between the D utch and Portuguese and the local Sinhalese) showed European features, but its gene frequencies were either intermediate to its parental pop ulations or more similar to the local Sinhalese. In the F statistic an alysis all populations showed positive F-IS values, ranging from 0.030 5 in the Burghers to 0.1084 in the Malays; however, for a large number of loci the F-IS values for the Burghers were negative, indicating th e possible hybrid nature of this population. In genetic affinity studi es the Burghers, Moors, and Malays showed a greater degree of isolatio n, but compared with the possible populations of their origin, the fiv e populations of Sri Lanka tended to show some degree of affinity to e ach other. Our analysis therefore suggests that there is little eviden ce of disruptive selection; however, restricted gene flow favors the c hange of allele frequency toward the local Sinhalese and Tamil populat ions.