The Indigenous population at the time of the first European settlements is estimated to have been between 200,000 and two million, with a figure of 500,000 accepted by Canada's Royal Commission on Aboriginal Peoples. As a consequence of European colonization, the Indigenous population declined by forty to eighty percent, and several First Nations, such as the Beothuk, disappeared. The decline is attributed to several causes, including the transfer of European diseases, such as influenza, measles, and smallpox to which they had no natural immunity, conflicts over the fur trade, conflicts with the colonial authorities and settlers, and the loss of Indigenous lands to settlers and the subsequent collapse of several nations' self-sufficiency.