Studies indicate the different ethno-religious groups of Iraq and Mesopotamia share significant similarities in genetics, and that Iraqi Mesopotamian Arabs are more genetically related to other non-Arab populations in the region such as Assyrians, Kurds, Iranians and Turks, as well as Levantines, than they are to Arabs of the Arabian peninsula. There are also significant differences in genetics between Mesopotamian Arabs compared to Arabs from Arabia and from countries like Saudi Arabia and Yemen. Semitic peoples of Iraq and the region, such as Iraqi Arabs and Assyrians are also more genetically related to each other than to non-Semitic populations such as the Indo-European populations like Iranians and Kurds, who are more genetically related, however they are all more closely genetically related that than they are to other members from other countries who speak the same language. The majority of Mesopotamian Arabs are also largely descendants of pre-Islamic indigenous peoples until they adopted the Arab identity in the 7th century during the Islamic conquest, and although Arab migrations may have taken place, they were minor and largely insignificant to the genetic demography of the region. Scientific studies on genetics of the peoples of the region has indicated: