sentences:  Since 1990, in the United States, physical anthropology and archaeological investigations based on the study of human remains are complicated by the Native American Graves Protection and Repatriation Act, (NAGPRA), which provides for the bodies of Native Americans and associated grave goods to be turned over to the recognized tribal body most legally affiliated with the remains.In some cases, notably, that of Kennewick Man, these laws have been subject to close judicial scrutiny and great intellectual conflict.Mesoamerica is a region and cultural area in the Americas, extending approximately from central Mexico to Honduras and Nicaragua, within which a number of pre-Columbian societies flourished before the Spanish colonization of the Americas in the 15th and 16th centuries.