The peopling of Europe involved successive waves of human migration and admixture, shaped by evolutionary adaptations in Africa and beyond. Human Evolution and Migration into Europe: DNA Evidence Timeline

The peopling of Europe involved successive waves of human migration and admixture, shaped by evolutionary adaptations in Africa and beyond. Genetic evidence from ancient DNA (aDNA) sequencing—primarily from autosomal genomes, Y-chromosome haplogroups, and mitochondrial DNA (mtDNA)—reveals three primary ancestral components in modern Europeans: Western Hunter-Gatherers (WHG), Early European Farmers (EEF, often associated with Anatolian Neolithic farmers), and Steppe pastoralists (linked to the Yamnaya culture). These components reflect Out-of-Africa migrations, post-glacial recolonization, Neolithic expansions, and Bronze Age Indo-European movements. Below is a staged timeline, substantiated by key aDNA studies.

Stage 1: Out-of-Africa Migration and Initial Settlement (ca. 45,000–40,000 years ago)

• Evolutionary Context: Modern humans (Homo sapiens) evolved in Africa ~300,000 years ago, with anatomical and behavioral modernity developing there. 
• A subset migrated out of Africa ~70,000–50,000 years ago via the Levant, carrying basal Eurasian ancestry.
• Migration to Europe: The first anatomically modern humans entered Europe ~45,000 years ago, replacing or marginally admixing with Neanderthals (who contributed ~1–2% Neanderthal DNA to non-African genomes via interbreeding ~50,000 years ago in the Near East).
• Population: Aurignacian culture bearers, ancestral to all later Europeans.

• DNA Evidence:

• Ust'-Ishim (Siberia, ~45,000 ya): Basal Eurasian-like individual with ~2% Neanderthal admixture (Fu et al., 2014, Nature).
• Bacho Kiro (Bulgaria, ~45,000 ya): Early European with Initial Upper Paleolithic toolkit; mtDNA haplogroup U (Hajdinjak et al., 2021, Nature).
• Post-Ice Age repopulation (~19,000–14,000 ya) from refugia (e.g., Iberia, Balkans) led to WHG formation.
• WHG exemplar: Loschbour (Luxembourg, ~8,000 ya) – ~80–100% WHG ancestry in Mesolithic Europeans; Y-haplogroup I2, mtDNA U5 (Lazaridis et al., 2014, Nature).

Stage 2: Last Glacial Maximum and Western Hunter-Gatherer Consolidation (ca. 40,000–8,000 years ago)

• Evolutionary Context: Adaptation to Ice Age Europe; dark skin initially (later light skin alleles selected post-Neolithic).
• Migration: Minimal large-scale movement; local hunter-gatherer groups persisted through the Last Glacial Maximum (~25,000–19,000 ya) in southern refugia.
• Population: WHG – dark-haired, blue-eyed foragers with high lactose intolerance.

DNA Evidence:


• Villabruna (Italy, ~14,000 ya): Marks WHG clade; carries derived SLC24A5/SLC45A2 alleles for light skin (post-LGM selection) (Olalde et al., 2014, Nature).
• WHG contribute 10–50% to modern Northern Europeans, highest in Baltics (50% in Estonians) (Haak et al., 2015, Nature).

Stage 3: Neolithic Transition and Early European Farmer Influx (ca. 8,500–6,000 years ago)

• Evolutionary Context: Shift from foraging to farming; selection for amylase genes (starch digestion) and lactase persistence (rare initially).
• Migration: Farmers from Anatolia (Near East, modern Turkey) spread via Southeast Europe 8,500 ya (Linear Pottery Culture, LBK), reaching Britain ~6,000 ya. They admixed with WHG (10–20% WHG in early farmers).
• Population: EEF – olive-skinned, brown-eyed agriculturalists; introduced crops (wheat, barley) and animals.

DNA Evidence:

• Anatolian Neolithic exemplar: Barcın (Turkey, 8,500 ya) – basal to EEF; low WHG (0%) (Mathieson et al., 2015, Nature).
• Stuttgart (Germany, ~7,000 ya): ~75% EEF + ~25% WHG; Y-haplogroup G2a (dominant in Neolithic farmers) (Lazaridis et al., 2014).
• Admixture modeling: EEF form ~40–80% of modern Southern Europeans (e.g., Sardinians ~80% EEF, closest to pure Neolithic) (Haak et al., 2015).

Stage 4: Bronze Age Steppe Migration and Yamnaya Admixture (ca. 5,000–4,000 years ago)

• Evolutionary Context: Domestication of horses; selection for height and immune genes.
• Migration: Yamnaya (Pontic-Caspian Steppe, Ukraine/Russia) expanded westward ~5,000 ya via Corded Ware Culture, replacing ~70% of Central European male lineages. They brought Indo-European languages, metallurgy, and wheeled vehicles.
• Population: Steppe pastoralists – tall, milk-drinking herders; admixed with WHG and EEF en route.

• DNA Evidence:

• Yamnaya exemplar: Samara (Russia, ~5,000 ya) – ~50% Eastern Hunter-Gatherer (EHG) + ~50% Caucasus Hunter-Gatherer (CHG); Y-haplogroup R1b (dominant in Western Europe today) (Allentoft et al., 2015, Nature).
• Corded Ware (Germany, ~4,500 ya): ~75% Yamnaya + ~25% EEF/WHG; rapid turnover evidenced by >90% steppe ancestry in Britain post-4,500 ya (Olalde et al., 2018, Nature).
• Modern gradient: Steppe ancestry ~20–50% (highest in Northern Europeans, e.g., Norwegians ~50%; lowest in Sardinians ~5%) (Haak et al., 2015).

• Post-Admixture Synthesis (ca. 4,000 years ago–Present) Final European Tripartite Model:
• Modern Europeans = f4(WHG, EEF, Yamnaya) with regional variation (e.g., British: ~40% EEF, ~40% Steppe, ~20% WHG)

• DNA Evidence Summary:

• Principal Component Analysis (PCA) and ADMIXTURE: Three clusters separate in ancient samples, converging in moderns (Lazaridis et al., 2014; Haak et al., 2015).
• qpAdm modeling: Quantifies proportions (e.g., Irish: 42% EEF, 43% Steppe, 15% WHG) (Cassidy et al., 2016, PNAS).
• No major post-Bronze Age inflows until historical eras (e.g., Roman, Slavic migrations <10% impact).

This framework is robust across >1,000 ancient genomes, with ongoing refinements from new samples (e.g., Iron Age continuity). DNA substantiates migrationism over purely autochthonous models, showing replacement and admixture as drivers of European genetic diversity.