Genetics
Modern-day genetic studies of the Y-chromosome suggest a close ethnic kinship between the Hutu and other neighboring Bantu peoples, particularly the Tutsi. Like the Tutsi, the Hutu largely belong to the E1b1a haplogroup (83%), which is associated with the Bantu expansion from West Africa. A minority carry the E2 (8%), B (4%), E1b1b (3%) and R1 (1%) clades.
generations of gene flow obliterated whatever clear-cut physical distinctions may have once existed between these two Bantu peoples -- renowned to be height, body build, and facial features. With a spectrum of physical variation in the peoples, Belgian authorities legally mandated ethnic affiliation in the 1920s, based on economic criteria. Formal and discrete social divisions were consequently imposed upon ambiguous biological distinctions. To some extent, the permeability of these categories in the intervening decades helped to reify the biological distinctions, generating a taller elite and a shorter underclass, but with little relation to the gene pools that had existed a few centuries ago. The social categories are thus real, but there is little if any detectable genetic differentiation between Hutu and Tutsi.
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