The high ancestral variability observed in whites and blacks suggests that each Brazilian has a singular and quite individual proportion of European, African and Amerindian ancestry in his/her mosaic genomes" (geneticist Sérgio Pena). The colonization of Brazil was characterized by a small proportion of women among the initial settlers. As there was a male predominance in the European contingent present in Brazil, most sexual partners of those settlers were, initially, Amerindian or African women, and, later, mixed-race women. This sexual asymmetry is marked on the genetics of the Brazilian people, regardless of skin color: there is a predominance of European Y chromosomes, and of Amerindian and African MtDNA. Haplogroup frequencies do not determine phenotype nor admixture. They are very general genetic snapshots, primarily useful in examining past population group migratory patterns. Only autosomal DNA testing can reveal admixture structures, since it analyzes millions of alleles from both maternal and paternal sides. Contrary to yDNA or mtDNA, which are focused on one single lineage (paternal or maternal) the autosomal DNA studies profile the whole ancestry of a given individual, being more accurate in describing the complex patterns of ancestry in a given place. In the Brazilian "white" and "pardos" the autosomal ancestry (the sum of the ancestors of a given individual) tends to be largely European, with often a non-European mtDNA (which points to a non-European ancestor somewhere up the maternal line), which is explained by the women marrying newly arrived colonists, during the formation of the Brazilian people.