Last time I checked Turks were originally from Ottomans origins.
This is so sad to hear these news about terrorist attacks...
First of all, Mongols and Turks lived together for a long time. During the time of Xiongnu Empire, Mongols and Turks weren't divided yet. East and North of Xiongnu was inhabited by Mongols. Todays Mongolia was inhabited by Turks. After the Xiongnu was defeated, the empire was divided to smaller states. Definitely Dinglins and West Xiongnu were Turkic. Probably North Xiongnus and South Xiongus (who were still one state) were mixed. Mongol ones were Xianbei and Wu-Huans. These two were the two main branches of the old Dong-hu who was defeated by Xiongnu.
After that, a small state called Wusun was divided from West Xiongnu. Their ethnicity is arguable. Some say that they are Turkic while some say that they are Indo-European. Wusun took the Ili Valley from Yuezhis.
After the West Xiongnu started to migrate far West to become the Huns, a new state; Hephthalite Empire was formed in the lands West Xiongnu left. There are several theories regarding the origins of the White Huns, with the Iranian and Turkic theories being the most prominent. For many years, scholars suggested that they were of Turkic stock .Some have claimed that some groups amongst the Hephthalites were Turkic-speakers. According to the Encyclopedia of the Peoples of Asia and Oceania the ancestry of the Hephthalites is still Uncertain but possibly Eastern Iranian within the larger Indo-European family for the majority. Some experts have also suggested the majority were of Turkic origins. They were certainly a mixed group who included peoples with many different origins. ... Probably dominated by Eastern Iranian language, but their mixed ancestry also led to multilingualism. (Wikipedia)
200 years after the formation of Hephtalites, the real seperation begins. There were Huns, Sabyrs, Hepthalites, Juan Juan, Dinglings, Tabgachs (Wei) and Kyrgyz. Juan Juans and Tabgachs were probably Mongols.
In 500 AD, when the Huns are done, they left Onogurs (to later mix with the Baltic people), Kutrigurs, Utrigurs, Alanians and Magyars.
565 AD, Gokturk Khaganate is formed. This is when the name "Turk" was officially in use.
600 AD, Gokturk Khaganate seperated. West Gokturks and East Gokturks. West Gokturks are todays Oghuz branch of Turkic people. They also had a little bit of Kipchak population because of Bashkorts and Kimeks while they also had the Karluk branch. East Gokturks are todays Kipchak and Sibir branches, plus Mongolians.
700 AD, one of the worst times in Turkic history probably. Onogurs+Magyars, Khazars, Avars (West), Bolgars, Pechenegs, Bashkors, Yakuts, Khakass, Turgesh, Karluk, Oghuz, Kimek, Idil Bolgar, Kyrgyz and East Gokturk. Think about ALL these and they ALL had their own states.
820 AD, rise of the Khazars.
1000 AD, Karakhanids, Idil Bolgars, Ghaznavids. New states huh? There also Seljuks trying to seperate themselves from Oghuz.
1055 AD, Seljuk Empire, pushing the gates of Anatolia. There are Aleppo, Armenia and Byzantine Empire on her way.
1071, Sultan Alparslan has won the Battle of Manzikert. Turks are in Anatolia!
1200, here comes the rise of Mongols. There are already Mongol states, such as Jalayirs, Merkits, Taichiuts and a really powerful one: Kara Khitai
1206, there comes Chinghis, the Mognols rise and establish one of the greatest empires history has ever seen.
So, how did they mix while having such tribe-states?
You know; to this date Mongols and Turkics lived together right? After the Mongol Empire is divided into four Mongol states, let "lived together" rise up, and create the "mixed together".
Chinghis Khaan used a tactic to prevent tribes from rebeling. He mix all the members of the suspicious tribes with all the members of another suspicious tribe or a very very calm tribe. So that "tribalism" is gone. They are a whole new faction now. This led to the mixing of Mongol and Turkic tribes.
Turkic population mostly outnumbered Mongol population in Central Asia. This led to the "Turkification" of Chagatais, "Turkification+Islamisation" of Altan Orda (Golden Horde) which already had incredible Turkic population. Ilkhanate probably remained the most Mongol, until the day they collapse and melt into Anatolia, Persia, Levant and Caucasus. Yuans became very Chinese. This has a really simple reason, Chinese culture always lured steppe people and melted them into itself. Chinese culture was strong, rich and complicated to the nomads.
Today
Today, Mongols and Turks share some similar traditions. I will not speak about Central Asia but Turkey, because that Turks and Mongols are probably the most distinct ones of our topic.