In July of 1991, nine skeletal remains were exhumed from a mass grave in Siberia, Russia. The bones were discovered near a place where a Russian royal family was murdered during the Russian revolution. People began to question if the bones belonged to Czar Nicholas and Czarina Alexandra, three of the daughters, their son Alexi, and three traveling servants. To answer this question, scientists turned to mitochondria DNA sequence polymorphisms. The mitochondria found in human cells contain a genome separate from the cells nuclear genome. T ....