Most prehistoric Europeans had dark skin, hair and eyes well into the Iron Age, about 3,000 years ago, new research finds.
Scientists found that the genes that cause lighter skin, hair and eyes emerged among early Europeans only about 14,000 years ago, during the late stages of the Paleolithic period — also known as the “Old Stone Age.” But these light features were only sporadic until relatively recently, said study senior author Silvia Ghirotto, a geneticist at the University of Ferrara in Italy.
Lighter skin may have carried an evolutionary advantage for Europeans because it enabled people to synthesize more vitamin D — needed for healthy bones, teeth and muscles — in Europe’s weaker sunlight. But lighter eye color — blue or green, for example — does not seem to have had major evolutionary advantages, and so its emergence may have been driven by chance or sexual selection, Ghirotto told Live Science in an email.
Ghirotto and her colleagues analyzed 348 samples of ancient DNA from archaeological sites in 34 countries in Western Europe and Asia, according to research published Feb. 12 on the preprint server bioRxiv, which hasn’t been peer-reviewed.
The oldest, from 45,000 years ago, was from the Ust’-Ishim individual discovered in 2008 in the Irtysh River region of western Siberia; and another high-quality DNA sample came from the roughly 9,000-year-old SF12 individual from Sweden.
But many of the older samples were badly degraded, and so the researchers estimated those individual’s pigmentation using “probabilistic phenotype inference” and the HIrisPlex-S system, which can predict eye, hair, and skin color from an incomplete DNA sample.
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Out of Africa
Palaeoanthropologists think the first Homo sapiens permanently arrived in Europe between 50,000 and 60,000 years ago, which meant they weren’t that far removed from their modern human ancestors in Africa. As a result, early Europeans initially only had genetics for dark skin, hair and eyes, which rely on hundreds of interconnected genes, Ghirotto said.
Even after lighter traits emerged in Europe about 14,000 years ago, however, they only appeared sporadically in individuals until relatively recent times — about 3,000 years ago — when they became widespread, she said.
The new study showed that the frequency of people with dark skin was still high in parts of Europe until the Copper Age (also known as the Chalcolithic period, which started about 5,000 years ago in Europe) and in some areas dark skin appeared frequently until even later, Ghirotto said.
Emerging traits
The researchers found that light eyes emerged among people in Northern and Western Europe between about 14,000 and 4,000 years ago, although dark hair and dark skin were still dominant at that time. (There are outliers, however. A 2024 genetic analysis showed a 1-year-old boy who lived in Europe about 17,000 years ago had dark skin, dark hair and blue eyes.)
The genetic basis for lighter skin seems to have emerged in Sweden at about the same time as lighter eyes, but initially it remained relatively rare, Ghirotto said.
The researchers also reported a statistical “spike” in the incidence of light eye color at this time, which suggested that blue or green eyes were more prevalent at that time than earlier or later.
Carles Lalueza Fox, a palaeogeneticist at Barcelona’s Institute of Evolutionary Biology, is an expert on early European pigmentation but was not involved in the latest study.
It was a “surprise” to learn that some European individuals had inherited genes for darker pigmentation up until the Iron Age, which was relatively recent in genetic terms, he told Live Science in an email.
While the new research charts the emergence of traits like lighter skin, hair and eyes, the reasons these traits could have become an evolutionary advantage are still not well understood, he added.
