Dienekes has a discussion up of a new paper on Iranian Y-chromosome variation. My post isn't prompted by the genetics here, but rather a minor historical note within the text which I want to correct, again, because it isn't totally minor in light of contemporary models of the uniqueness of Iranian (specifically Persian) identity in the Middle East:
Persian identity refers to the Indo-European Aryans who arrived in Iran about 4 thousand years ago (kya). Originally they were nomadic, pastoral people inhabiting the western Iranian plateau. From the province of Fars they spread their language and culture to the other parts of the Iranian plateau absorbing local Iranian and non-Iranian groups. This process of assimilation continued also during the Greek, Mongol, Turkish and Arab invasions. Ancient Persian people were firstly characterized by the Zoroastrianism. After the Islamization, Shi'a became the main doctrine of all Iranian people.
As Dienekes observes I've objected to this confusion before:
For example, it is routinely unknown that before the Safavids Iran was a predominantly Sunni domain. This is not to deny the presence of Shia within the borders of modern Iran, but aside from periods of state patronage (e.g., the Buyids) the status of Shi’ism was as it was in most of the Muslim world after the year 1000, a marginal minority, tolerated at best, oppressed at worst. It was the Safavids, originally a cosmopolitan Sufi order of variegated Greek, Kurdish, and Turkic origin (albeit, culturally Turk by the period of the Safavids) which realigned the identity of the Iranian nation with Shi’ism in the 16th and 17th centuries, recruiting Shia clerics from Lebanon and Iraq to reform and convert the multi-ethnic populace of the Iranian plateau.
In other words, it seems likely that Shia identity became a necessary part of Iranian, and Persian, identity only after ~1700, when the Safavid project of religious transformation entered its terminal phase of completion. The Tajiks of Central Asia, who speak a variant of Persian, remain overwhelmingly Sunni. Not surprisingly they were not under the same Safavid domination as their western cousins. Why does it matter? Because modern thinkers seem to conflate Shia history with Persian history, and assume that the two have some inextricable connection. The lack of knowledge that the Persians were mostly Sunni before the early modern era is widespread. Two of the authors on the above paper are ethnic Iranians, so unless they did not read the paper's final text they simply let that through out of ignorance. I've seen other Iranians, adjudged experts on their nation, propagate this falsehood. Then again, how much American history do most Americans know? Very little. So I don't judge that too harshly. Addendum: For those readers who wish to "school" me by pointing out the heterodox religious enthusiasms, often with a sympathy toward the Shia camp, of the early Abbassids, I'm aware of that. If you wish to enter into a discussion why don't think this counts, I'm game. For example, it seems ethnic Persians were still mostly Zoroastrian in this period, and the locus of Shia dissent is suspiciously correlated with regions of Arab military encampments. In other words, early Shia strength in Iran corresponded with Arab, not non-Arab, ethnicity.