Australian archaeology is a large sub-field in the discipline of archaeology. Archaeology in Australia takes four main forms: Aboriginal archaeology (the archaeology of Aboriginal and Torres Strait Islander people in Australia before and after European settlement), historical archaeology (the archaeology of Australia after European settlement), maritime archaeology and the archaeology of the contemporary past (after the Second World War). Bridging these sub-disciplines is the important concept of cultural heritage management, which encompasses Aboriginal and Torres Strait Islander sites, historical sites, and maritime sites. Archaeological studies or investigations of Aboriginal and Torres Strait Islander people and culture in Australia have had many different agendas through time. Initial archaeological investigation was often focused on finding the oldest sites. By the 1970s, archaeological research was concerned with the environment and the way it impacted on humans. In the late 1970s cultural heritage management gained prominence, with the increasing demands by Australian Aboriginal and Torres Strait Islander groups for representation in archaeological research. At a research level the focus shifted to cultural change of Australian Aboriginal and Torres Strait Islander people through time. Currently, archaeological research places great importance on Australian Aboriginal and Torres Strait Islander people's viewpoints on the land and history of Australia. Consideration is given to Australian Aboriginal and Torres Strait Islander people's belief that archaeological sites are not just capsules of the past but a continuation from the past to the present. Therefore, at a research level significance is placed on the past but also on the importance of the present. Prehistory of Australia The first settlement of Australia is a popular research topic both in archaeology and in the public arena. There is consensus that no human or closely related species evolved independently in Australia.