From the Steppes to the Mountains: The Long Journey of Indo-Europeans into East Asia

Thousands of years before the Silk Road, other routes linked East and West—carried not by caravans, but by genes.

Introduction: A Genetic Odyssey Across Eurasia

The term "Indo-European" often evokes the languages of Europe and northern India. Yet recent genetic research reveals a much broader reach—stretching deep into the heart of East Asia. In a groundbreaking 2021 study published in Nature, Wang et al. analyzed the genomes of over 500 ancient individuals from the eastern Eurasian steppe, uncovering multiple waves of migration, admixture, and cultural transformation over the past 10,000 years.

Among the findings, a surprising thread emerged: traces of Western Steppe Herder (WSH) ancestry—hallmarks of early Indo-European migrations—woven into the genetic fabric of populations from Mongolia to western China.

Steppe Origins: The Rise of the Yamnaya Legacy

The Indo-European expansion began in the Pontic-Caspian steppe around 3000 BCE, with the Yamnaya culture and its pastoralist lifestyle. These groups carried a distinct genetic profile, now termed "WSH ancestry," defined by a combination of Eastern European Hunter-Gatherer and Caucasus-related lineages.

Through successive waves, this genetic signature spread eastward:

First through the Afanasievo culture (~3000–2500 BCE), whose remains in the Altai region (e.g., sample SSGM16) are nearly indistinguishable from the Yamnaya.
Later, via the Sintashta and Andronovo horizons (~2000–1500 BCE), associated with early Indo-Iranian speakers and more complex admixture with local populations.

Afanasievo in the East: A Genetic Footprint Without Cultural Survival

The Afanasievo were the earliest known bearers of Indo-European ancestry in East Asia. Sample SSGM16, from the Altai Mountains, shows near-total WSH ancestry, confirming a direct migration from the west without local admixture.

Yet, this group appears to vanish genetically and culturally within a few centuries. By the time of the Chemurchek culture (~2500–1800 BCE), individuals like AYIM22BN display significant admixture with Iranian-related ancestry, possibly from BMAC or a similar source—suggesting new migration waves or long-distance contacts.

The Iron Age Resurgence: Indo-European Echoes in the Scythians and Xiongnu

A second pulse of Indo-European ancestry swept eastward during the Bronze and Iron Ages, driven by mobile warrior-pastoralist groups:

Saka and Scythians, thriving across the central steppe, were genetically diverse but retained substantial WSH components.
Among the Xiongnu, the confederation that challenged Han China, some elite individuals carry significant steppe and even Iranian-related ancestry, suggesting a complex, multi-ethnic elite class.

Samples such as KHOI12 from late Iron Age Mongolia show admixture patterns that echo both earlier WSH signals and local East Asian ancestries—an emblem of cultural blending on the frontiers of ancient empires.

Language vs. Genes: The Indo-European Mystery in the East

Despite this genetic footprint, no Indo-European language survived in East Asia. Why?

Several factors may explain this paradox:

The early Afanasievo were too few in number to sustain linguistic dominance.
Later steppe groups, although influential, often merged with powerful local cultures, especially Sino-Tibetan or Altaic-speaking ones.
The dominance of Sinitic civilizations to the east and Iranian-speaking cultures to the west created a linguistic corridor where Indo-European roots struggled to survive.

For those interested in further analysis or visualization, here are the G25 coordinates for each of the mummies Haber et al., 2019:

Copy

China_Tarim_EMBA2:11KBM1,0.104717,-0.118817,0.078441,0.199938,-0.088016,0.05271,-0.041127,-0.053998,-0.035587,-0.086015,0.022572,-0.012739,0.02334,-0.052985,0.002443,0.02612,-0.003651,0.007095,-0.003771,-0.01013,-0.057773,0.011376,0.019843,0.02663,0.002155
China_Xinjiang_Ayituohan_Afanasievo_BA.SG:AYIM22BN.SG,0.111547,0.028435,0.048271,0.12694,-0.052933,0.051595,-0.014806,-0.016384,-0.039064,-0.06925,0.006658,-0.009741,0.004608,-0.037158,0.030266,0.022408,-0.003651,-0.000507,-0.004777,0.008254,-0.009733,0.001978,0.003204,0.020846,-0.002395
China_Xinjiang_Ayituohan_Afanasievo_BA.SG:AYIM22BY.SG,0.105855,0.013202,0.05242,0.114666,-0.054164,0.038208,-0.012221,-0.007384,-0.047245,-0.073441,0.003897,-0.004346,0.012933,-0.038534,0.039087,0.014585,-0.017732,0.004307,0.002137,-0.004377,-0.006114,0.005317,0.016885,0.018918,-0.011735
China_Xinjiang_Nileke_Afanasievo_BA.SG:G218M5-2.SG,0.108132,-0.010155,0.059208,0.123387,-0.063396,0.039324,-0.014571,-0.025384,-0.046018,-0.074899,0.008931,0.004796,0.004757,-0.048443,0.029858,0.018165,-0.005607,-0.000633,-0.011313,0.005378,-0.020838,0.010634,0.021322,0.023377,-0.005149
China_Xinjiang_Nileke_Afanasievo_BA.SG:G218M5-3N.SG,0.104717,-0.036559,0.056568,0.115312,-0.060627,0.03514,-0.021386,-0.022384,-0.037428,-0.069432,0.00341,0.002847,0.02661,-0.040736,0.035016,0.008088,-0.017602,0.000253,0.000251,0.004627,-0.021712,0.011747,0.012571,0.025184,-0.005628
China_Xinjiang_Beifang_Xiaohe_BA.SG:GMGM1.SG,0.09675,-0.116786,0.072784,0.197677,-0.112021,0.038487,-0.043947,-0.059074,-0.044586,-0.101688,0.031016,-0.015586,0.028989,-0.069224,0.019137,0.028772,-0.029206,-0.00114,-0.00993,0.003877,-0.043922,0.003586,0.023417,0.005061,-0.008143
China_Xinjiang_Xiaohe_BA:L5209,0.104717,-0.100537,0.072784,0.203491,-0.117253,0.0502,-0.051232,-0.062767,-0.043564,-0.098954,0.030691,-0.014837,0.033003,-0.073766,0.028908,0.026651,-0.014864,-0.003547,0.003897,-0.003377,-0.050661,0.013231,0.032784,0.021449,-0.003473
China_Xinjiang_Xiaohe_BA:L5213,0.101303,-0.102568,0.072784,0.199938,-0.11356,0.052153,-0.049117,-0.065766,-0.049904,-0.099501,0.027444,-0.01169,0.021556,-0.075004,0.030809,0.024662,-0.01369,-0.001267,0.002765,-0.011255,-0.049662,0.007419,0.016515,0.013616,-0.003712
China_Xinjiang_Xiaohe_BA:L6101,0.106994,-0.092413,0.076555,0.196062,-0.106481,0.035977,-0.049352,-0.050536,-0.039064,-0.087838,0.022734,-0.009741,0.01888,-0.064545,0.021172,0.025192,-0.014994,0.003547,0.003645,-0.000625,-0.053531,-0.003462,0.020582,0.013978,-0.003592
China_Xinjiang_Xiaohe_BA:L6103,0.104717,-0.100537,0.075801,0.199615,-0.115406,0.049085,-0.043477,-0.058613,-0.0452,-0.095674,0.025495,-0.015886,0.022299,-0.07294,0.024973,0.017369,-0.012908,-0.00038,0.001257,-0.012256,-0.052532,0.006306,0.020336,0.013134,-0.017962
China_Xinjiang_Xiaohe_BA:L6105,0.09675,-0.102568,0.07467,0.207367,-0.1231,0.047133,-0.050292,-0.058151,-0.037632,-0.094398,0.039136,-0.014087,0.025124,-0.073766,0.025515,0.014187,-0.030771,-0.001014,-0.003645,-0.012381,-0.05091,0.01694,0.024773,0.019762,-0.006107
China_Xinjiang_Xiaohe_BA:L6106,0.097888,-0.099522,0.067505,0.207044,-0.113252,0.051874,-0.049117,-0.056536,-0.03211,-0.088385,0.027606,-0.013188,0.026016,-0.05849,0.03013,0.019358,-0.013038,0.0019,0.004274,-0.01113,-0.052408,0.01014,0.029826,0.018918,-0.012214 
China_Xinjiang_Songshugou_Afanasievo_BA.SG:SSGM16.SG,0.120652,0.026404,0.051288,0.136307,-0.048009,0.039602,-0.005875,-0.016153,-0.05379,-0.078179,0.01023,-0.001349,0.007582,-0.039222,0.043159,0.017104,-0.013169,-0.003294,-0.006159,0.004502,-0.016471,0.003586,0.011216,0.024943,-0.003952
China_Xinjiang_Xiaohe_BA.SG:XHM100.SG,0.105855,-0.105615,0.073161,0.208659,-0.112636,0.041834,-0.045122,-0.064613,-0.035178,-0.10515,0.029392,-0.013038,0.017988,-0.0706,0.024158,0.024264,-0.017602,-0.00076,-0.00352,-0.013006,-0.048789,0.013231,0.020582,0.016508,-0.002994
China_Xinjiang_Xiaohe_BA.SG:XHM110.SG,0.108132,-0.093429,0.067505,0.199292,-0.111405,0.044623,-0.051937,-0.049152,-0.044177,-0.096585,0.021922,-0.014987,0.018434,-0.071701,0.032301,0.024131,-0.021644,-0.000887,0.00176,0.002876,-0.052657,0.007048,0.020706,0.01217,-0.00958
China_Xinjiang_Xiaohe_BA.SG:XHM135.SG,0.106994,-0.100537,0.071276,0.192509,-0.119407,0.051595,-0.047942,-0.059536,-0.046222,-0.096221,0.033452,-0.016186,0.023786,-0.062343,0.021172,0.018828,-0.020079,-0.008361,-0.001006,-0.001501,-0.050161,0.004946,0.023664,0.015062,-0.008861
China_Xinjiang_Xiaohe_BA.SG:XHM75.SG,0.111547,-0.094444,0.068636,0.208982,-0.118484,0.048248,-0.045357,-0.065074,-0.033542,-0.098772,0.02582,-0.009292,0.027948,-0.077482,0.026058,0.02148,-0.026207,0.002407,-0.002514,-0.003001,-0.044422,0.019908,0.032661,0.016749,-0.011855

Conclusion: The Steppe as a Crossroads, Not a Border

The story told by ancient genomes is not one of simple replacement, but of repeated contact, blending, and transformation. From Yamnaya horse riders to Xiongnu chieftains, the Indo-European presence in East Asia is a testament to the deep connectivity of the Eurasian continent long before written records.