Yes, the majority of them are turkified Mongols. According to the
y-dna composition of Kazakhs, they carry the same set of y-dna haplogroups as Mongols (C2b*, C-M86, C-M401, C-M407, D1a etc.). In the
image above, in case the names are not understood, they are Mongols, Kyrgyz, Afghan Tajiks/Uzbeks/Turkmens/Hazara/Pashtuns, Pakistani, Iranians and Kazakhs, respectively. The mongolic starcluster is C-M401 (and its father sucblace C-M504) and it is observed that it is present in 13% of Kyrgyz, 4% of Uzbeks, 1.4% of Turkmens, 33.3% of Hazara, 7% of Pakistani men and approximately 15% of Kazakhs.
Even if other y-dna C had a different history at their beginning, like Oirat C-m86, forest Mongolic/Buryat C-m407, when they moved into Kazakhstan they were obviously already mongolic-speaking by then. Although the y-dna composition seems to be a conglomeration of different haplogroups, it is often clear-cut when we dive into specific Kazakh tribes. Therefore, Argyns are mainly y-dna G1 (G-L1323), Naimans are mainly y-dna O2, Qongirat are C-M407, Kipchaks are R-M73/Q-M25 (still hasn't been resolved which of the two), Shanyshkyly are C-F4002 (subclade of M401), Uysyns are also C-F4002, Tore are C-F1756, Alimuly are C-F992. Alshyn are C-M48 and so on. You can read more here in this
Kazakhstani research by Sabitov and Jabagin. The turkic element comes from Kipchaks and some other tribes in Northeastern Kazakhstan who are y-dna Q. The mongolic element is more prevalent in the south and west of the country, where we find
the Senior zhuz and the Junior Zhuz and tribes like Jalair and Uysyns with mongolic origin.
Orta zhuz (Middle Zhuz) are mostly the earlier inhabitans of Kazakhstan (e.g. Argyns) or later allies of the Mongols (Naimans, Kipchaks).
Regarding C-M407, it is a subclade of C-CTS2657, which is prevalent in Koreans. Mongolic tribes which have a high frequency of C-M407 (Qongirat, Buryat) usually have ethnonyms which are reminiscent of old Korean ones like Qoguryeo, Buyeo. So the coalescence of C-M407 must have happened at a very early stage inside a mongolic speaking environment. These tribes are also characteristic of being semi-farming and semi-nomadic, unlike full scale nomadic mongolic tribes. C-M86, a subclade of C-M48, is higher among Oirats in western Mongolia, Oirat-origin tribes in Kazakhstan and Kalmyks (30%, with only 10% C-M401), who are Oirat-speaking.
An anecdote about this, regarding the Dzhunghar genocide, is that Mongols are angry against Manchu for that decision against an ally nation. But it is now known that the ruling class of Manchu, Aisin Gioro, is y-dna C-M401, coming from the Daur (descendants of para-mongolic Khitan people, also high in C-M401) and Dzhunghars (essentially Oirats) in western Mongolia/Xinjiang Uyghur are C-M86, the main Manchu y-dna haplogroup (taking into account the tungusic origins of Manchu). So it is maybe Mongols that should apologize to Manchu for that genocide.
Finally, an
excerpt from wikipedia states that:
According to a large-scale Kazakhstani study published in 2017, Kazakh males belong to Y-DNA haplogroups C2-M217 (658/1294 = 50.85%, including 322/1294 = 24.88% C-M401, 225/1294 = 17.39% C-M86, 80/1294 = 6.18% C-M407, and 31/1294 = 2.40% C-M217(xM401, M48, M407)), R-M207 (157/1294 = 12.13%, including 78/1294 = 6.03% R1a-M198, 41/1294 = 3.17% R1b-M478, 21/1294 = 1.62% R1b-M269, 13/1294 = 1.00% R2-M124 (predicted), and 4/1294 = 0.31% R-M207(xM198, M478, M269, M124)), O-M175 (140/1294 = 10.82%, including 122/1294 = 9.43% O-M134, 9/1294 = 0.70% O-M122(xM134), and 9/1294 = 0.70% O-M175(xM122)), J-M304 (106/1294 = 8.19%, including 53/1294 = 4.10% J2a-M410 (predicted), 50/1294 = 3.86% J1-M267 (predicted), and 3/1294 = 0.23% J-M304(xJ1, J2a)), N-M231 (69/1294 = 5.33%, including 49/1294 = 3.79% N-M46, 16/1294 = 1.24% N-P43, and 4/1294 = 0.31% N-M231(xP43, M46)), G-M201 (64/1294 = 4.95%, including 44/1294 = 3.40% G1-M285, 18/1294 = 1.39% G2-P287, and 2/1294 = 0.15% G-M201(xM285, P287)), Q-M242 (41/1294 = 3.17%), E-M35 (23/1294 = 1.78%), I-M170 (20/1294 = 1.55%, including 11/1294 = 0.85% I2a-L460 (predicted), 5/1294 = 0.39% I1-M253 (predicted), and 4/1294 = 0.31% I2b-L415 (predicted)), D-M174 (6/1294 = 0.46%), L-M20 (4/1294 = 0.31% (predicted)), H (3/1294 = 0.23% (predicted)), T (2/1294 = 0.15% (predicted)), and K* (1/1294 = 0.08%).[54] However, the distribution was inhomogeneous for some Y-DNA haplogroups: Q-M242 was found predominantly among members of the Qangly tribe (27/40 = 67.50%), C-M407 was found predominantly among members of the Qongyrat tribe (64/95 = 67.37%), O-M134 was found predominantly among members of the Naiman tribe (102/155 = 65.81%), N-M46 was found predominantly among members of the Syrgeli tribe (21/32 = 65.63%), J1-M267 (predicted) was found predominantly among members of the Ysty tribe (36/57 = 63.16%), G1-M285 was found predominantly among members of the Argyn tribe (26/50 = 52.00%), R1b-M478 was found predominantly among members of the Qypshaq tribe (12/29 = 41.38%), and R1a-M198 was found with notable frequency among members of the Suan (13/41 = 31.71%) and Oshaqty (8/29 = 27.59%) tribes and among members of the Qoja caste of Islamic scholars and gentlemen (6/30 = 20.00%), although C-M401 was more common than R1a-M198 among members of the Suan and Oshaqty tribes (25/41 = 60.98% and 11/29 = 37.93%, respectively). Because of this lack of homogeneity among Kazakhs in regard to Y-chromosome DNA, the real percentage of present-day Kazakhs who belong to each Y-DNA haplogroup may differ from the percentages found in this study depending on the proportion of each tribe in the total population of Kazakhs.
The linguistic turkification might have happened in one of the following three ways:
1. The region of Kazakhstan had already been turkified by previous turkic-speaking ruling dynasties, like the Gokturk khaganate, so Mongols had to learn turkic to communicate with their subjects.
2. The linguistic conversion happened in a military environment, before the onset of the expedition, voluntarily, or under a Kipchak leadership. It has to be taken into account that vast areas in Central Asia carry mongolic-specific (either Tungusic, or Korean etc.) haplogroups, so it is unlikely they would independently involve into turkic-speaking simultaenously after their seperation.
3. According to a theory that suggests that Kazakhstan was turkified by a later wave from Kipchaks from Kyrgyzstan who are high in C-F1756, a haplogroup which has a slightly different history from C-M504.
