"According to the Canadian anthropologist Peter Frost, the current level of hair colour diversity in Europe would have taken 850,000 years to develop, while Homo sapiens has been in Europe no longer than 45,000 years. This is evidence enough that genes for fair hair were inherited from interbreeding with Neanderthals."
https://www.eupedia.com/europe/neanderthal_facts_and_myths.s...
"According to the Canadian anthropologist Peter Frost, the current level of hair colour diversity in Europe would have taken 850,000 years to develop, while Homo sapiens has been in Europe no longer than 45,000 years. This is evidence enough that genes for fair hair were inherited from interbreeding with Neanderthals."