Genetic structure of native Andean populations from Argentina inhabiting different altitudes

On the basis of erythrocyte and serum protein polymorphisms, we investigate d the level of genetic differentiation among 3 Argentinian native populatio ns sharing ethnic and morphological characteristics but inhabiting differen t altitudes in the Andes. Of the 15 loci studied, 8 are monomorphic. Phenot ype distribution of the polymorphic systems are in agreement with Hardy-Wei nberg equilibrium, except for malic enzyme (MOD), where a silent allele was found. The 2 highland populations exhibit a close genetic similarity, prob ably as a result of intense gene flow, The lowland population shows reduced genetic diversity, which suggests the influence of stochastic phenomena su ch as the founder effect.