Great Rift ValleyThe Great Rift Valley is a series of contiguous geographic trenches, approximately in total length, that runs from Lebanon in Asia to Mozambique in Southeast Africa. While the name continues in some usages, it is rarely used in geology as it is considered an imprecise merging of separate though related rift and fault systems. This valley extends northward for 5,950 km through the eastern part of Africa, through the Red Sea, and into Western Asia.
ExtinctionExtinction is the termination of a taxon by the death of its last member. A taxon may become functionally extinct before the death of its last member if it loses the capacity to reproduce and recover. Because a species' potential range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxa, where a species presumed extinct abruptly "reappears" (typically in the fossil record) after a period of apparent absence.
Trinomial nomenclatureIn biology, trinomial nomenclature refers to names for taxa below the rank of species. These names have three parts. The usage is different in zoology and botany. In zoological nomenclature, a trinomen (), trinominal name, or ternary name refers to the name of a subspecies. Examples are Gorilla gorilla gorilla (Savage, 1847) for the western lowland gorilla (genus Gorilla, species western gorilla), and Bison bison bison (Linnaeus, 1758) for the plains bison (genus Bison, species American bison).
Type (biology)In biology, a type is a particular specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally associated. In other words, a type is an example that serves to anchor or centralizes the defining features of that particular taxon. In older usage (pre-1900 in botany), a type was a taxon rather than a specimen.
Nilotic peoplesThe Nilotic peoples are people indigenous to the Nile Valley who speak Nilotic languages. They inhabit South Sudan, Sudan, Egypt, Ethiopia, Uganda, Kenya, the Democratic Republic of the Congo, Rwanda, Burundi and Tanzania. Among these are the Burun-speaking peoples, Karo peoples, Luo peoples, Ateker peoples, Kalenjin peoples, Datooga, Dinka, Nuer, Atwot, Lotuko, and the Maa-speaking peoples. The Nilotes constitute the majority of the population in South Sudan, an area that is believed to be their original point of dispersal.
