Although the production of domestic cattle has been around for a fairly long time, not much was known about the underlying genetics and modern genome. Finding a 6736 BC Aurochs humerus bone in England in 1998 was the first step at uncovering the history behind cattle. Researchers have since completed matrilineal mitochndrial DNA (mtDNA) analyses, whole nuclear genome sequencing, and runs of homozygosity tests. These genetic analysis tests have allowed researchers to accurately determine the origins and ancestral history of domestic cattle, distinguish between natural and artificial selection of key traits (behavior, production, and health), evaluate the influence of gene flow and genetic isolation, and how domestication events have shaped modern cattle.