Many cultures have legends concerning the origins of marriage. Several theories concern the evolutionary origins of warfare. There are a number of theories regarding the subsequent origins of religious practices. They do have myths about external origins. The biological origins of introns are obscure. There are several theories regarding the origins of Euchre. There are three paradigms for understanding the origins and basis of nationalism. The exact origins of slavery are not known. The United States is home to people of many different ethnic origins. His origins and motives remain unclear. Tolkien proposed several theories for the origins of orcs. All Western historiography was during that time obsessed with the quest of "origins". Chiropractic is classified as a field of pseudomedicine on account of its esoteric origins. This finding helped establish the biological origins of petroleum. The population of Bulgaria descend from peoples with different origins and numbers.