An autosomal study from 2011 (with nearly almost 1000 samples from all over the country, "whites", "pardos" and "blacks" included, according to their respective proportions) has also concluded that European ancestry is the predominant ancestry in Brazil, accounting for nearly 70% of the ancestry of the population: ""In all regions studied, the European ancestry was predominant, with proportions ranging from 60.6% in the Northeast to 77.7% in the South"". The 2011 autosomal study samples came from blood donors (the lowest classes constitute the great majority of blood donors in Brazil), and also public health institutions personnel and health students. In all Brazilian regions European, African and Amerindian genetic markers are found in the local populations, even though the proportion of each varies from region to region and from individual to individual. However most regions showed basically the same structure, a greater European contribution to the population, followed by African and Native American contributions: "Some people had the vision Brazil was a heterogeneous mosaic [...] Our study proves Brazil is a lot more integrated than some expected". Brazilian homogeneity is, therefore, greater within regions than between them: