This is a pertinent question that many middle-easterners have pondered. Which of the many of the earliest peoples and civilizations are modern middle-eastern populations descendents of? It is question difficult to answer, due to the highly dynamic nature of the area, lack of detailed documentation and the intense population movements. Factors that have made the task of identifying these exceedingly difficult, unlike more peripheral and historically isolated regions in the world. However, I believe that the recent discoveries within archaeo-genetics and sequencing of members of prehistoric groups in the region has been immensely helpful in giving us profound insights into this issue.
There are 2 populations that are important for the formation of the modern west-iranic people.
The pre-iranian populations that had already settled in the zagros since the Chalocolithic(5000 B.C and onward), and the later oncomers, the Central-Asian Indo-Iranian immigrants who arrived during the bronze age from the steppes of central-asia. The former was important for the foundation of the civilizations and cultures, such as elamites, kassites, manneans, gutians. They in overall share a similar material culture, and their ancestral contribution is formative for the overall genetic character of the modern west-iranians, while latter had a profound cultural and linguistic impact. Many people within the Iranosphere, for sentimental, nationalist or romantic folk reasons, like to empathize Indo-Iranian heritage. Emerging genetic evidence however seems to suggest that while their genetic impact in the Iranian plateau was significant and widespread, it was relatively small. In-comparison to the east-Iranian speaking populations( Such as the Pashtoons of Afghanistan, Pamiri speakers of the Pamir valley) in South-Central Asia, who seem to have received significantly more admixture from the Indo-Iranian speaking steppe groups, based on existing genetic models. This is largely due to their ancestors closer proximity to the Indo-Iranian homeland. The Indo-Iranians, seem to have played a role, much like the later Turkic immigrations, as the cultural and lingustic patrons of the regions they conquered and settled, with a limited minor genetic contribution. This is consistent with the elite dominance theory. That is: a small conquering elite, ruling a larger subjugated populace. Regardless, their impact was significant enough to alter the genetic affinities of pre-iranian zagros populations, to the point that modern west-iranics do not genetically cluster with pre-iranian zagros populations. I will demonstrate this later in the post.
Recently the Paleo-Geneticist Lazaridis et. al and his team, released the study findings of their latest comprehensive paper on the prehistoric cultures on neolithic farmers in West-Asia that they have sequenced. The perhaps single most important finding related to our issue, is the sequencing of several iranian-chalocolithic genomes from chalocolithic aged human remains.The chalocolithic was an interim period between the late neolithic and the early bronze age. The Iranian-chalocolithic samples would therefore be representative of the pre-iranian populations who settled the western part of the iranian plateau. As they apparently, completely lack indo-iranian steppe admixture. Which can be seen here, in this modified PCA plot created by the Eurogenes blog author David(with modifications for the readers, note all credits goes to david of eurogenes for making this PCA plot):
As one can observe by looking at the PCA plot. The indicated modern West-Iranian groups are substantially genetically shifted towards steppe groups compared to the Iranian chalocolithics. Which is the main reason for why they cluster with Transcaucasians(who also have significant European like ancestry, via different waves into the caucasus) rather than chalocolithic era iranians.
So this naturally leads to the question. How much Indo-Iranian ancestry exists in modern day west-iranian groups? David from eurogenes made a qpAdm model estimate with samples from various iranian groups available which is useful in giving us weighted insight:
Iran_Chalcolithic 0.136 ± 0.121
Iran_Neolithic 0.631 ± 0.152
Yamnaya_Samara 0.164 ± 0.033
Han 0.026 ± 0.017
Yoruba 0.044 ± 0.013
Iran_Chalcolithic 0.723 ± 0.078
Iran_Neolithic 0.106 ± 0.079
Yamnaya_Samara 0.130 ± 0.024
Han 0.041 ± 0.011
Iran_Chalcolithic 0.558 ± 0.066
Iran_Neolithic 0.209 ± 0.065
Yamnaya_Samara 0.178 ± 0.022
Han 0.055 ± 0.010
Iran_Chalcolithic 0.617 ± 0.064
Iran_Neolithic 0.181 ± 0.062
Yamnaya_Samara 0.148 ± 0.022
Han 0.054 ± 0.010
With Iran_Neoithic and Iran_Chalocolithic serving as proxies for pre-indo-iranian ancestry, Han as an ENA proxy for ASI affinity, and finally Yamnaya_Samara as proxy for indo-iranian ancestry. While Yamnaya_Samara is less than ideal, it serves as a decent rough estimate of steppe ancestry.
Noteworthy is how the Lurs(who are related to Feylis), clearly have the highest estimate of Pre-Indo-Iranian ancestry, compared to Mazanderanis, a North-West iranian group. Which is in line with their topgraphic location and the history of Indo-Iranian immigrations, concentrating more heavily in North-Western Iranian areas, which also meshes quite nicely with north-iranian groups higher euro-like affinity in different genetic tools.
Curious as to the rate of steppe admixture in Feylis. I asked David to model the available Feyli samples as part Yamnaya, Sintashta, and Andronovo(The last two being representatives of proto-indo-iranian steppe groups). And he came up with this:
Iran_Chalcolithic 0.707 ± 0.070
Iran_Neolithic 0.125 ± 0.072
Yamnaya_Samara 0.139 ± 0.023
Han 0.029 ± 0.011
Iran_Chalcolithic 0.615 ± 0.070
Iran_Neolithic 0.174 ± 0.066
Andronovo 0.185 ± 0.028
Han 0.026 ± 0.011
Iran_Chalcolithic 0.626 ± 0.066
Iran_Neolithic 0.138 ± 0.062
Sintashta 0.191 ± 0.030
Han 0.045 ± 0.010
As one can see here, the Feylis are as predicted, very similar to Khorramabadi Lurs. This is in line with the historical and ethnological relationship between the groups.
The low estimate for indo-iranian ancestry is supported by the available the haplogroup assignments of who are almost exclusively near-eastern. The R1a1-Z93 branch, which is associated with steppe expansions into south-asia, south-central asia and west-iran, and widespread in modern day indo-iranain speakers at relatively significant frequencies. Is completely absent in feylis, who almost completely display near-eastern related mutations, a list of assignments which can be viewed in the post here:
Feyli DNA haplogroups
In the next installment I'll go more in-depth into the historical candidates for the feyli ancestors.
Special thanks to David from Eurogenes for providing the above material.
The genetic structure of the world's first farmers
qpADm tour of iran