Genetecists have shown with genetical data that the cultivated carrot germplasm is subdivided between Eastern and Western carrots (Clotault et al. 2010). The black/purple carrots are clustered in the Eastern group, even if three individuals from Middle East show admixture between the two geographical groups. This suggests the black type has an oriental origin, and that gene flows between this type and European carrots may have arisen in Turkey/Syria.
via Black Carrots.