Ancient DNA Suggests Early Emergence of European Pigmentation Profile, Highlighting Local Adaptation

Recent discussions in ancient human genetics point to an early appearance of a "modern European pigmentation profile," encompassing light skin, blue eyes, and potentially blonde hair in ancient individuals. Geneticist Razib Khan recently commented on this, stating that an ancient human appears to be "the first human who seems to have had a record of something like the modern european pigmentation profile. light skin, blue eyes, AND, possibly blonde hair." This observation emphasizes the significant role of local adaptation in shaping human traits, even amidst extensive population movements.

The evolution of these distinct features in Europe was a complex, multi-stage process rather than a singular event. Scientific understanding indicates that light skin, largely influenced by genes such as SLC24A5 and SLC45A2, became prevalent due to strong natural selection, likely linked to vitamin D synthesis in regions with reduced sunlight. Blue eyes, primarily associated with the HERC2/OCA2 gene region, also emerged early, with some ancient individuals, such as Motala 12 from Sweden around 7,700 years ago, displaying both light skin and blue eyes.

The inclusion of "possibly blonde hair" in this early profile, as noted by Khan, adds a layer of complexity to the timeline. While light skin and blue eyes are well-documented in ancient European populations, blonde hair is generally considered to have become more widespread later in prehistory. Khan's specific mention suggests either a new interpretation of existing data or reference to a particular ancient genome that hints at this combination.

A core aspect highlighted by Khan is that this pigmentation profile "keeps reoccurring over despite massive population replacements indicates local adaptation." This phenomenon suggests that genetic variants conferring advantages for pigmentation were repeatedly favored by natural selection within various populations inhabiting Europe, even as new groups migrated into the continent. Such findings underscore the powerful and persistent influence of environmental pressures on human genetic evolution over millennia.

This ongoing research into ancient DNA provides crucial insights into the dynamic interplay between human migration, genetic adaptation, and the diverse phenotypic traits observed across contemporary populations. The complex mosaic of European pigmentation serves as a compelling example of how natural selection can preserve and spread beneficial traits across vast timescales.