{"id":284366,"date":"2025-06-09T21:14:53","date_gmt":"2025-06-09T21:14:53","guid":{"rendered":"https:\/\/peraltafinancing.com\/anthropology\/rethinking-neanderthal-expansion-into-eurasia\/"},"modified":"2025-06-09T21:14:53","modified_gmt":"2025-06-09T21:14:53","slug":"rethinking-neanderthal-expansion-into-eurasia","status":"publish","type":"post","link":"https:\/\/fivemor.com\/?p=284366","title":{"rendered":"Rethinking Neanderthal Expansion into Eurasia"},"content":{"rendered":"


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For decades, the story of Neanderthal migration into Asia has remained patchy\u2014more shadow than shape. Fossil finds in Siberia and genomic data hinted at a major dispersal from Western to Eastern Eurasia sometime between 120,000 and 60,000 years ago. But how Neanderthals got there, what routes they took, and whether their migration was slow or swift have remained open questions.<\/p>\n

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Computer simulated paths of Neanderthal dispersals demonstrate they could have reached the Altai Mountains in Siberia within 2,000 years during warm climatic conditions in one of two ancient time periods\u2014MIS 5e (approximately 125,000 years ago) or MIS 3 (approximately 60,000 years ago)\u2014as demonstrated by the three different possible paths shown here. These paths follow a northern route through the Ural Mountains and southern Siberia, often intersecting with known archaeological sites from the same time periods. Credit: Emily Coco and Radu Iovita<\/figcaption><\/figure>\n<\/div>\n

Now, a study in <\/span>PLOS One<\/span><\/em> offers a striking hypothesis: Neanderthals may have crossed the 2,000-mile span between the Caucasus Mountains and the Altai region of Siberia in less than two millennia, not through an organized trek, but as an emergent outcome of everyday mobility.<\/span><\/p>\n

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\u201cNeanderthal dispersal into the Altai wasn’t the result of deliberate navigation toward a destination,\u201d<\/em> explained Emily Coco, the study\u2019s lead author. <\/span>\u201cIt was a product of locally informed movements shaped by landscape and climate.\u201d<\/em><\/p>\n<\/blockquote>\n

The archaeological sites between the western Caucasus and the Altai Mountains are few. Genetic links between Neanderthals in Europe and those excavated in Chagyrskaya Cave suggest at least one major eastward movement. Yet, the archaeological breadcrumbs are too sparse to map out a firm path.<\/p>\n

To explore how such a migration might have occurred, Coco and her colleague Radu Iovita turned to agent-based modeling. Instead of assuming that Neanderthals charted optimal or known paths\u2014an unlikely behavior for foragers in unknown terrain\u2014they built a simulation where agents moved across a cost-weighted landscape. This method allowed for random movement choices within the constraints of rivers, mountains, and ice, mirroring how foragers likely navigated in the Pleistocene.<\/p>\n

The simulated \u201cagents\u201d were dropped into either the northern or southern Caucasus and allowed to move using what’s known as a L\u00e9vy walk\u2014favoring short distances with occasional long steps\u2014reflecting the stochastic nature of foraging behavior. If they entered \u201cnew territory,\u201d their range expanded, modeling the behavior of early colonizers.<\/p>\n

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\u201cWe wanted to test if a long-distance migration could simply emerge from the ordinary decisions Neanderthals would make based on their local environment,\u201d<\/em> the authors noted.<\/span><\/p>\n<\/blockquote>\n

Out of 110 simulation runs, only three agents reached the Altai Mountains within a range of 500 kilometers. But all three successful migrations took less than 2,000 years\u2014a blink in archaeological time\u2014and followed similar routes.<\/p>\n

The common path: a broad northern arc through the Volga and Kama river valleys, across the Urals, and along the Irtysh River into southern Siberia. Rivers\u2014especially those running roughly east-west\u2014functioned as conduits rather than barriers.<\/p>\n

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\u201cThese corridors would have provided reliable water, game, and directionality,\u201d<\/em> said Iovita. <\/span>\u201cWhat we\u2019re seeing is the skeleton of a migration shaped more by rivers than by intentions.\u201d<\/em><\/p>\n<\/blockquote>\n

Interestingly, the agents avoided the southern Caspian corridor, a path previously proposed in earlier models. Transgressions of the Caspian Sea likely rendered that route impassable during glacial periods.<\/p>\n

The timing of these simulated journeys coincides with two warm periods in the Late Pleistocene: Marine Isotope Stage (MIS) 5e and MIS 3. Both are marked by interglacial climates, retreating ice, and more hospitable steppe landscapes.<\/p>\n

The warm stages offered not just habitable conditions, but geographic connectivity. For instance, during MIS 5e, river valleys were likely more stable, glaciers less extensive, and the terrain easier to traverse.<\/p>\n

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\u201cDispersal during warm phases aligns with the environmental tolerances of Neanderthals,\u201d<\/em> the authors explained. <\/span>\u201cThese weren\u2019t polar pioneers\u2014they followed the seasons.\u201d<\/em><\/p>\n<\/blockquote>\n

The implications go beyond movement. The agents’ simulated paths intersected with regions inhabited by Denisovans, another archaic human lineage. Genetic data already suggest Neanderthals and Denisovans interbred multiple times, including in the Altai.<\/p>\n

The model lends spatial context to that genomic record: these riverine corridors weren\u2019t just routes of travel\u2014they were zones of contact.<\/p>\n

While the model aligns well with the genetic record and a few archaeological finds, its value lies in hypothesis generation, not confirmation. Many of the modeled migration steps occurred in regions still archaeologically invisible\u2014places where perishable campsites would leave scant trace.<\/p>\n

But the simulation does more than suggest a route. It reorients how researchers think about mobility in prehistory. Instead of imagining migrations as linear pilgrimages, the model supports a more diffused process\u2014where large movements are the cumulative product of thousands of local decisions.<\/p>\n

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\u201cIt wasn\u2019t a march,\u201d<\/em> Coco emphasized. <\/span>\u201cIt was a drift\u2014shaped by rivers, slopes, climate, and chance.\u201d<\/em><\/p>\n<\/blockquote>\n