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
Tutsi after mid-1600. Beginning in about 1880, Roman Catholic missionaries arrived in the Great Lakes region. Later, when German forces occupied the area during World War I, the conflict and efforts for Catholic conversion became more pronounced. As the Tutsi resisted conversion, missionaries found success only among the Hutu. In an effort to reward conversion, the colonial government confiscated traditionally Tutsi land and reassigned it to Hutu tribes. In Burundi, meanwhile, Tutsi domination was even more entrenched. A ruling faction, the Ganwa, soon emerged from amongst the Tutsi and assumed effective control of the country's administration. The area was ruled as