Moroccans descended from Berbers, Arabs, and Black Africans exactly like the neighboring Maghrebians. The Berbers are the prehistoric populations of Morocco and are related to the wider group of Paleo-Mediterranean peoples. The Afroasiatic family may have originated in the Mesolithic period, perhaps in the context of the Capsian culture.
Epidemiologic triangle model of disease causation. A common model used in public health illustrates the relationships among an agent, a host and the environment. It applies to biological, chemical and physical agents.
epidemiology. the science concerned with the study of the factors determining and influencing the frequency and distribution of disease, injury, and other health-related events and their causes in a defined human population for the purpose of establishing programs to prevent and control their development and spread.