Origins of Hutu, Tutsi and Twa of neighboring people, it was almost non-existent among Rwandan Tutsi. Presence of the sickle cell trait is evidence of survival in the presence of malaria over many centuries, suggesting differing origins. Regional studies of the ability to digest lactose are also supportive. The ability to digest lactose among adults is widespread only among desert-dwelling nomadic groups that have depended upon milk for millennia. Three quarters of the adult Tutsi of Rwanda and Burundi have a high ability to digest lactose, while only 5% of the adults of the neighboring Shi people of eastern Congo can. Among Hutu, one in three
History of Burundi that provided for a president, non-ethnic government, and a parliament. Burundi's first Hutu president, Melchior Ndadaye, of the Hutu-dominated Front for Democracy in Burundi (FRODEBU) Party, was elected in 1993. Ndadaye was assassinated three months later, in October 1993, by Tutsi army extremists. The country’s situation rapidly declined as Hutu peasants began to rise up and massacre Tutsi. In acts of brutal retribution, the Tutsi army proceeded to round up thousands of Hutu and kill them. The Rwandan Genocide in 1994, sparked by the killing of Ndadaye’s successor Cyprien Ntaryamira, further aggravated the conflict in Burundi by sparking additional massacres