Genetic studies on Jews show that most Jews worldwide bear a common genetic heritage which originates in the Middle East, and that they bear their strongest resemblance to the peoples of the Fertile Crescent. The genetic composition of different Jewish groups shows that Jews share a common genetic pool dating back 4,000 years, as a marker of their common ancestral origin. Despite their long-term separation and beside their shared genetic origin, Jews also maintained a common culture, tradition, and language.