Archaeology can be seen as part of anthropology or as a sister discipline. In anthropological studies, archaeology can provide a time dimension beyond that available from oral tradition, and usually from history. Archaeology is based primarily on the evidence of material culture, related in a contextual framework. Its theory overlaps with that of anthropology, often showing similar developments, but archaeology cannot usually study individual human relationships in the past as a basis for generalization, and consequently must base its interpretations on other patterning in the evidence. The two disciplines have sometimes tended toward fission, but many archaeologists draw on anthropology to the extent that their work becomes part of anthropology, and many anthropologists, especially those interested in an evolutionary timescale, draw extensively on archaeological evidence and interpretation.