Ancient East Eurasians

The term Ancient East Eurasian, alternatively also known as East Eurasian or Eastern Eurasian, is used in population genomics to describe the genetic ancestry and phylogenetic relationship of diverse populations primarily living in the Asia-Pacific region, belonging to the "Eastern Eurasian clade" of human genetic diversity,  and which can be associated with the Initial Upper Paleolithic (IUP) wave, following the Out of Africa migration (>60kya).

Dispersal
Modern humans of the Initial Upper Paleolithic wave (IUP) are suggested to have expanded from a population hub through a star-like expansion pattern (>45kya), and are linked to the "East Eurasian" lineage, broadly ancestral to modern populations in Eastern Eurasia, Oceania, and the Americas, notably East Asians, Southeast Asians, Indigenous Siberians, Aboriginal Australians, Papuans, Pacific Islanders, and mostly in Indigenous Americans,and partly in South Asians and Central Asians. While certain Initial Upper Paleolithic populations represented by specimens found in Central Asia and Europe, such as the Ust'-Ishim man, Bacho Kiro or Oase 2, are inferred to have used inland routes, the ancestors of all modern East Eurasian populations are inferred to have used a Southern dispersal route through South Asia, where they subsequently diverged rapidly.

Ancient East Eurasians diverged from Ancient West Eurasians around 46,000 years ago, and started to diversify themselves 45,000 years ago. This divergence most likely occurred in the Persian Plateau.

Lineages
Major East Eurasian ancestry lineages which contributed to modern human populations include the following:

The Australasian, Ancient Ancestral South Indian, and East and Southeast Asian lineages display a closer genetic relationship to each other than to any non-Asian lineages, and together represent the main branches of "Asian-related ancestry", which diverged from each other >40kya. The Australasian lineage however received higher archaic admixture in the Oceania region, and may also harbor some small amounts of "xOoA" admixture from an earlier human dispersal, which did not contribute to any other human population. Alternatively, Australasians can be described as nearly equally admixture between a "Basal East Asian" source (represented by Tianyuan) and a deeper East Eurasian lineage not sampled yet.
 * Australasian lineage — refers to an ancestral population that primarily contributed to human populations in a region consisting of Australia, Papua, New Zealand, neighboring islands in the South Pacific Ocean and parts of the Philippines. Represented by present-day Australasians, e.g. Papuans and Aboriginal Australians, as well as the Philippine Negritos.
 * Ancient Ancestral South Indian lineage — refers to an ancestral population that primarily contributed to Indigenous South Asians. Partially represented by 5,000 – 1,500 year old Indus Periphery individuals as well as modern South Asians. Highest presence among tribal groups of southern India like the Paniya and Irula. While the lineage is occasionally represented by the distantly related Andamanese peoples, serving as an imperfect proxy, the Andamanese groups are genetically closer to the 'Basal East Asian' Tianyuan man.
 * East and Southeast Asian lineage — refers to an ancestral population that primarily contributed to humans living in East and Southeast Asia, much of Remote Oceania, as well as Siberia and the Americas. Represented by ancient Tianyuan and Hoabinhian specimens and present-day East and Southeast Asians.

Traces of an unsampled deeply diverged East Eurasian lineage can be observed in the genome of ancient and modern inhabitants of the Tibetan Plateau. While modern Tibetans mostly derive their ancestry from a northern East Asian source (specifically Yellow River farmers), a minor, but significant contribution stems from a deeply diverged East Eurasian local "Ghost population" that was distinct from other deeply diverged lineages such as Ust'Ishim, Hoabinhian/Onge or Tianyuan, representing the local Paleolithic population of the Tibetan Plateau.

Deeper IUP-associated East Eurasian lineages have been associated with the remains of the Ust'-Ishim man from Siberia, and the Oase and Bacho Kiro cave specimens in southeastern Europe, and represent early inland migrations, deeply diverged from all other East Eurasian populations. These deep East Eurasian populations did not contribute to later Eurasian populations, except small contributions to the Goyet Caves specimen of Europe. The exact substructure and relationship between these deeper East Eurasian lineages is not well resolved yet.