This relaxed or reversed selection allowed variants at genes like SLC45A2, SLC24A5, and others that reduce pigmentation to increase in frequency.

But this process takes time.

Tens of thousands of years of selection, accumulating across many generations, are required to substantially change the frequency of pigmentation variants in a population.

At 45,000 years ago, the modern human populations in Europe had not had nearly that long.

They had arrived in central Europe very recently, from source populations in western Asia and ultimately Africa, and the selection pressures had barely begun to act.

The ancient DNA evidence across multiple specimens confirms this picture consistently.