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
Rwanda Nziza under the presidencies of Gregoire Kayibanda and Juvénal Habyarimana, were marked by continued cycles of violence, culminating in the 1990s with the launch of the Rwandan Civil War by exiled Tutsi led by Paul Kagame, the assassination of President Habyarimana, and the 1994 Rwandan Genocide, in which between 500,000 and 1,000,000 Tutsi and politically moderate Hutu were killed by Hutu extremists, on the orders of the interim government, in the space of just 100 days. The genocide was ended when Kagame's rebel army took control of the country in July 1994. A period of reconciliation began, as a unity government