Modern Assyrians descend from Ancient Mesopotamians such as ancient Assyrians and Babylonians, originating from the ancient indigenous Mesopotamians of Akkad and Sumer, who first developed the civilisation in northern Mesopotamia (modern-day Iraq) that would become Assyria in 2600 BCE.
A 2008 study on the genetics of “old ethnic groups in Mesopotamia”, including 340 subjects from seven ethnic communities (“Assyrian, Jewish, Zoroastrian, Armenian, Turkmen, the Arab peoples in Iran, Iraq, and Kuwait”) found that Assyrians were homogeneous with respect to all other ethnic groups sampled in the study, regardless of religious affiliation.