Indigenous peoples are the earliest known inhabitants of an area, especially one that has been colonized by a now-dominant group. However, usage of the term and who may qualify as being Indigenous vary depending on nationality and culture. In its modern context, the term Indigenous was first used by Europeans, who used it to differentiate the Indigenous peoples of the Americas from the European settlers of the Americas, as well as from the sub-Saharan Africans the settlers enslaved and brought to the Americas by force. The term may have first been used in this context by Sir Thomas Browne in 1646, who stated "and although in many parts thereof there be at present swarms of Negroes serving under the Spaniard, yet were they all transported from Africa, since the discovery of Columbus; and are not indigenous or proper natives of America." Peoples are usually described as "Indigenous" when they maintain traditions or other aspects of an early culture that is associated with the first inhabitants of a given region. Not all Indigenous peoples share this characteristic, as many have adopted substantial elements of a colonizing culture, such as dress, religion or language. Indigenous peoples may be settled in a given region (sedentary), exhibit a nomadic lifestyle across a large territory, or be resettled, but they are generally historically associated with a specific territory on which they depend. Indigenous societies are found in every inhabited climate zone and continent of the world except Antarctica. There are approximately five thousand Indigenous nations throughout the world. Indigenous peoples' homelands have historically been colonized by larger ethnic groups, who justified colonization with beliefs of racial and religious superiority, land use or economic opportunity. Thousands of Indigenous nations throughout the world currently live in countries where they are not a majority ethnic group. Indigenous peoples continue to face threats to their sovereignty, economic well-being, languages, ways of knowing, and access to the resources on which their cultures depend. Indigenous rights have been set forth in international law by the United Nations, the International Labour Organization, and the World Bank. In 2007, the UN issued a Declaration on the Rights of Indigenous Peoples (UNDRIP) to guide member-state national policies to the collective rights of Indigenous peoples, including their rights to protect their cultures, identities, languages, ceremonies, and access to employment, health, education and natural resources. Estimates of the total global population of Indigenous peoples usually range