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 only one dominated by an opposition party. Opposing the genocide, Habyalimana was able to keep relative calm in the province, until he was deposed by the extremist Sylvain Ndikumana. Finding the population of Butare resistant to murdering their fellow citizens, the government flew in militia from Kigali by helicopter, and they readily killed the Tutsi. Most of the victims were killed in their own villages or in towns, often by their neighbors and fellow villagers. The militia typically murdered victims with machetes, although some army units used rifles. The Hutu gangs searched out victims hiding in churches and school buildings,