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 is defined as the branch of medicine that finds out what causes epidemics and how to control them. An example of epidemiology is the branch of medicine that includes the group of professionals who tracked down the cause of AIDS.