For details on when the east met with the west, see this webmaster's discussion on the Huns, the Yuezhi, the Tarim Mummies, the Yuezhi-Yushi misnomer, the Mongoloid-Caucasoid admixture at 2000 B.C.E., the fallacy of the Aryan bearing of the Chinese civilization, the fallacy of the Yuezhi jade trade, the Yuezhi migration timeline, as well as the location of the Kunlun Mountain, Queen Mother of the West, the legendary book of mountains and seas at the Imperial China blog, and the Qiang's possible routes of passage into Chinese Turkestan at http://www.imperialchina.org/Barbarians.htm which was embedded within the Huns.html and Turks_Uygurs.html pages. (Note that Western Queen Mother had the prototype in an "earth mother" deity, not related to Queen Sheba of Charles Hucker. The Mt. Kunshan jade was more likely the Mt. Huoshan jade in the Han dynasty book Huai Nan Zi, or the Mt. Yiwulü jade or the Kunlun jade that were juxtaposed together in the same book Huai Nan Zi, not related to Queen Mother of the West. http://www.sino-platonic.org/complete/spp115_chinese_proto_indo_european.pdf provides another perspective of looking at things of the past from the perspective of language cognates. Rather believing that the Indo-Europeans ever invaded China and gave the Sinitic people the language, we could actually deduce that "Old Chinese", for its 43% correlation with the Proto-North-Caucasian, rather 23% with the Proto-Indo-European, was the source for both the cognates of the Proto-North-Caucasian and the Proto-Indo-European -- with the Proto-North-Caucasian falling under the umbrella of the Dene-Caucasian (Sino-Caucasian) Language Family that encompassed the [Proto-North-]Caucasian, Yeniseian and Sino-Tibetan languages. This is because our cousins, i.e., the N haplogroup people, relocated to North Asia and then to Latvia, Estonia, Finland and Scandinavia, bringing along the Sinitic language to the Proto-North-Caucasian who in turn gave it to the Proto-Indo-European. Note the Sinitic language cognates' 74% correlation with the Proto-Tibeto-Burman who split from the Sinitic people merely 5000-6000 years ago.)
 
Li Hui of Fudan University of China analyzed the Asian DNAs to have derived a conclusion that ancestors of the [East] Asians possessed a distinctive Mark M89 by the time they arrived in Southeast Asia. About 30,000 years ago, from the launching pad of Southeast Asia, the early Asians went through a genetic mutation to marker M122. Li Hui claimed that the early migrants to the Chinese continent took three routes via two entries of today's Yunnan and Guangxi-Guangdong provinces. More studies done after Li Hui had ascertained the dates of the O1, O2 and O3 haplogroup people, with the (O1, O2) entrants along the Southeast Chinese coast dated to have split away from the O3-haplogroup people like 20,000 years ago, much earlier than the continental peers, i.e., the Sino-Tibetans (O3a3c1-M117), Hmong-Mien (Miao-Yao, O3a3b-M7) and Mon-khmers. According to https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5255561/ "Y chromosome suggested Tibeto-Burman populations are an admixture of the northward migrations of East Asian initial settlers with haplogroup D-M175 in the Late Paleolithic age, and the southward Di-Qiang people with dominant haplogroup O3a2c1*-M134 and O3a2c1a-M117 in the Neolithic Age. Haplogroup O3a2c1*-M134 and O3a2c1a-M117 are also characteristic lineages of Han Chinese, comprising 11.4% and 16.3%, respectively. However, another dominant paternal lineage of Han Chinese, haplogroup O3a1c-002611, is found at very low frequencies in Tibeto-Burman populations, suggesting this lineage might not have participated in the formation of Tibeto-Burman populations." Namely, the haplogroup O3a1c-002611 Sinitic people, not the O3a2c1*-M134 and O3a2c1a-M117 barbarians, were responsible for engendering the Yangshao and Longshan civilization, and partially with the N-haplogroup people, engendering the Hongshan civilization. The Zhou people were archaeologically speculated to have origin from today's Shanxi for the link to the Guangshe Culture –- which was in turn a derivative of the You'ao-type Laohushan Culture of the mixed N-haplogroup and O-haplogroup people. (Since the O3a1c-002611 people were separated from the Northwestern cousins and Tibeto-Burmese at an early age, for it to have a part in the history of Northwestern China, the explanation would be to treat the Haplogroup O3a2c1*-M134 and O3a2c1a-M117 people as the historical Qiang and Hu barbarians, with the latter's paleo-Northwestern genes replacing the paleo-North-China and paleo-Central Plains genes of O3a1c-002611 Sinitic people by the Soong dynasty (A.D. 960-1279), that was likely triggered by the multiplication of the Tang dynasty's imperial house that had its origin from the Western Corridor. The Soong dynasty royals took Tianshui of western China as the ancestral homeland, which was similar to the Tang dynasty royals' origin from the Western Corridor in western China, i.e., the Qin and Zhao states' common ancestral place. The Soong royal house, however, could be of the Shatuo Turks' Q-haplogroup gene. Also see this webmaster's discussion on the ethnic nature of the ancient Huns belonging to part of the epic Jiang-rong human migration of the Jiang-surnamed San-miao people and Yun-surnamed Xianyun people.)
 
Li Hui commented that one branch of the early Asians, over 10,000 years ago, entered China's southeastern coastline with genetic marker M119. Li Hui, claiming the same ancestry as the Dai-zu and Shui-zu minorities of Southwestern China, firmly believed that his ancestors had dwelled in the Hangzhou Bay and the Yangtze Delta for 7-8 thousand years. The people with the M119 marker would be the historical "Hundred Yue People". The interesting theory adopted by Li Hui would be the migration of one branch of people who continued to travel non-stop along the Chinese coastline to reach the Liao-he River area of today's Manchuria. Li Hui's speculation on basis of the DNA technology was an evolving process. This would be likely the O2-haplogroup people, rather than the C-haplogroup or North Asia people whose historical presence in Asia could be dated 50,000 years ago, just after the earlier D-haplogroup people who were now mostly restricted in the area of Hokkaido, Japan, and known as the Ainu. The C-haplogroup people developed into what this webmaster called by the Altaic-speaking people, i.e., ancestors of the Mongols and Manchus. What likely happened was that the O2-haplogroup people first travelled along the coast to reach Manchuria, and then traced back towards the south to reach the Yangtze area about 7-8000 years ago, where they evicted the O1-haplogroup people to the Southeast Asian islands. At about the same time, the O3-haplogroup people, moving through the continent, reached today's western Liaoning at least 5000 years ago, or like 11,000 years ago on basis of the evidence of the pottery aging. See the genetical analysis conducted by Li Hongjie of Jirin University on the remains of prehistoric people extracted from the archaeological sites.

  Northeast (southeastern Inner Mongolia)
    Niuheliang, Lingyuan, the Hongshan Culture, 5000 YBP, 
    4 N, 1 C*, 1 O

  North
   Yuxian County (the Sanguan site), Hebei, 
   the Lower Xiajiadian Culture, 3400-3800 YBP, all O3