Unraveling Ancient Skins: Pigmentation Insights from Ancient DNA

This study delves into the fascinating world of ancient genetics, specifically focusing on the skin, hair, and eye colour of early Europeans determined through their DNA. The team, led by researchers like Silvia Perretti and Guido Barbujani, uses a statistical method known as genotype likelihood to analyze ancient DNA samples.

• The first light-skinned individuals appeared in the Mesolithic period (14,000-4,000 years ago).
• During the Bronze Age (7,000-3,000 years ago), the proportion of dark-skinned people was still significant.
• During the Iron Age (3,000-1,700 years ago), light skin color began to dominate.

The real turning point was the spread of Neolithic farmers, who arrived from Anatolia 10,000 years ago. These early farmers carried genes for lighter skin, which probably gave them an evolutionary advantage in the less sunny climate of Europe. Their genes spread over time, but the process was slow and uneven. 
Traditionally, lighter skin has been thought to have evolved to enhance vitamin D production, but new evidence suggests that diet may have played a key role. As humans evolved from small nomadic groups to larger, agricultural communities, their diets changed. They relied less on wild game, which was rich in vitamin D, and more on cultivated plants, which lacked the vitamin. This change, along with the need to absorb more sunlight in northern latitudes, may have led to the development of lighter skin."

https://www.origo.hu/tudomany/2025/02/bor-sotet-volt-europaban


The actual paper:

Abstract:

Light eyes, hair and skins probably evolved several times as Homo sapiens dispersed from Africa. In areas with lower UV radiation, light pigmentation alleles increased in frequency because of their adaptive advantage and of other contingent factors such as migration and drift. However, the tempo and mode of their spread is not known. Phenotypic inference from ancient DNA is complicated, both because these traits are polygenic, and because of low sequence depth. We evaluated the effects of the latter by randomly removing reads in two high-coverage ancient samples, the Paleolithic Ust’-Ishim from Russia and the Mesolithic SF12 from Sweden. We could thus compare three approaches to pigmentation inference, concluding that, for suboptimal levels of coverage (<8x),  a probabilistic method estimating genotype likelihoods leads to the most robust predictions. We then applied that protocol to 348 ancient genomes from Eurasia, describing how skin, eye and hair color evolved over the past 45,000 years. The shift towards lighter pigmentations turned out to be all but linear in time and place, and slower than expected, with half of the individuals showing dark or intermediate skin colors well into the Copper and Iron ages. We also observed a peak of light eye pigmentation in Mesolithic times, and an accelerated change during the spread of Neolithic farmers over Western Eurasia, although localized processes of gene flow and admixture, or lack thereof, also played a significant role.

Inference of human pigmentation from ancient DNA by genotype likelihood Silvia Perretti, Maria Teresa Vizzari, Patrícia Santos, Enrico Tassani, Andrea Benazzo, Silvia Ghirotto, Guido Barbujani bioRxiv 2025.01.29.635495; doi: https://doi.org/10.1101/2025.01.29.635495 

This is a preprint and has not been certified by peer review