Excellent link, my friend! So they are , indeed, related to Proto-Turkic peoples.
Not exactly. Proto-Turkics are Altaic siberians related to Yakuts who are 60-100% East Asian:
Proto-Turkic language - Wikipedia, the free encyclopedia
Xiongnu - Wikipedia, the free encyclopedia
Saka on the other hand are Iranic tribes:
Saka - Wikipedia, the free encyclopedia
Kingdom of Khotan - Wikipedia, the free encyclopedia
Yuezhi - Wikipedia, the free encyclopedia
Indo-Scythians - Wikipedia, the free encyclopedia
"The ancestors of the Indo-Scythians are thought to be
Sakas (
Scythian) tribes.
"One group of Indo-European speakers that makes an early appearance on the
Xinjiang stage is the Saka (Ch. Sai). Saka is more a generic term than a name for a specific state or ethnic group; Saka tribes were part of a cultural continuum of early nomads across Siberia and the Central Eurasian steppe lands from Xinjiang to the Black Sea. Like the Scythians whom
Herodotus describes in book four of his
History (
Saka is an Iranian word equivalent to the Greek
Scythos, and many scholars refer to them together as Saka-Scythian), Sakas were Iranian-speaking horse nomads who deployed chariots in battle, sacrificed horses, and buried their dead in barrows or mound tombs called
kurgans."
[7]
Yuezhi expansion
In the 2nd century BC, a fresh
nomadic movement started among the
Central Asian tribes, producing lasting effects on the history of
Rome in
Europe and
Bactria,
Kabul,
Parthia and India in the east. Recorded in the annals of the
Han dynasty and other
Chinese records, this great tribal movement began after the
Yuezhi tribe was defeated by the
Xiongnu, fleeing westwards after their defeat and creating a
domino effect as they displaced other central Asian tribes in their path.
According to these ancient sources
Modu Shanyu of the Xiongnu tribe of
Mongolia attacked the
Yuezhi and evicted them from their homeland between the
Qilian Shan and
Dunhuang. Leaving behind a remnant of their number, most of the population moved westwards.
[8]
Early Indian literature records military alliances between the Sakas, Kambojas, Pahlavas and Paradas. Ancient Puranic traditions mention several joint invasions of India by Scythians. The conflict between the
Bahu-Sagara of India and the
Haihaya-Kamboja-Saka-Pahlava-Parada is well known as the war fought by "five hordes" (
pāňca-ganha). The Sakas, Yavanas, Tusharas and Kambojas also fought the
Kurukshetra war under the command of
Sudakshina Kamboja. The
Valmiki Ramayana also attests that the Sakas, Kambojas, Pahlavas and Yavanas fought together against the
Vedic,
Hinduking
Vishwamitra of
Kanauj.[
citation needed] (doubtful)
Around 175 BC, the
Yuezhi tribes (possibly related to the
Tocharians who lived in eastern
Tarim Basin area), were defeated by the
Xiongnu tribes, and fled west into the
Ili river area. There, they displaced the
Sakas, who migrated south into
Ferghana and
Sogdiana. According to the Chinese historical chronicles (who call the Sakas, "Sai" 塞):
"The Yuezhi attacked the king of the Sai who moved a considerable distance to the south and the Yuezhi then occupied his lands" (
Hanshu 61 4B).
Sometime after 155 BC, the Yuezhi were again defeated by an alliance of the
Wusun and the
Xiongnu, and were forced to move south, again displacing the Scythians, who migrated south towards
Bactria, and south-west towards
Parthia and
Afghanistan.
The Sakas seem to have entered the territory of the
Greco-Bactrian Kingdom around 145 BC, where they burnt to the ground the Greek city of
Alexandria on the Oxus. The Yuezhi remained in Sogdiana on the northern bank of the
Oxus, but they became
suzerains of the Sakas in Bactrian territory, as described by the Chinese ambassador
Zhang Qian who visited the region around 126 BC.
In Parthia, between 138–124 BC, the Sakas tribes of the
Massagetae and
Sacaraucae came into conflict with the
Parthian Empire, winning several battles, and killing successively King
Phraates II and King
Artabanus I.
The Parthian king
Mithridates II finally retook control of Central Asia, first by defeating the Yuezhi in Sogdiana in 115 BC, and then defeating the Scythians in Parthia and
Seistan around 100 BC.[
citation needed]
After their defeat, the Yuezhi tribes migrated into Bactria, which they were to control for several centuries, and from which they later conquered northern India to found the
Kushan Empire."
Pashtuns just like Punjabi's may be remnants of this tribe. In both places they got mixed with pre-existing local population and the reason why they look different and have different genetic make up. Muslim ruling families in these areas of course got genetic contribution from later Turkic and Turko-Mongol invasions.
Its possible that Sikh's may have some small admixture from East Asian neighbors from those early times, but its no longer noticeable. Genetic admixture study may be able to reveal the extent of any North East Asian genes in Sikh population.
So my best guess:
Yuezhi/Tokharian Iranic + ANI (Ancestral North Indian) + ASI (Ancestral South Indian) = Sikh
