Origins of Hutu, Tutsi and Twa phenotype, genotype, cultural memory of inhabitants of Rwanda, archeology, and linguistics. Most Tutsis and Hutus carry the E1b1a paternal haplogroup, which is common among Bantu populations. More recent studies have de-emphasized physical appearance, such as height and nose width, in favor of examining blood factors, the presence of the sickle cell trait, lactose intolerance in adults, and other genotype expressions. Excoffier et al. (1987) found that the Tutsi and Hima, despite being surrounded by Bantu populations, are "closer genetically to Cushites and Ethiosemites". Another study concluded that, while the sickle cell trait among the Rwandan Hutu was comparable to that
Rwandan genocide own, but by this stage the Hutu had full backing from the Belgian administration who wanted to overturn the Tutsi domination. In early 1960, the Belgians replaced most Tutsi chiefs with Hutu and organised mid-year commune elections which returned an overwhelming Hutu majority. The king was deposed, a Hutu dominated republic created, and the country became independent in 1962. As the revolution progressed, Tutsi began leaving the country to escape the Hutu purges, settling in the four neighbouring countries: Burundi, Uganda, Tanzania and Zaire. These exiles, unlike the Banyarwanda who migrated during the pre-colonial and colonial era, were regarded as