It's historically been the case that fossil remains of Neanderthals paint an incomplete picture; they can't tell us about their cognitive skills or really give us details of what they looked like.
But scientists at the Max Planck Institute in Leipzig started looking into the DNA of Neanderthals and they made some astonishing discoveries. They discovered the human variant of the FOXP2 gene in our nearest relatives and an interesting detail: at least one percent of the Neanderthals in Europe may have had red hair.
Only two percent of the world's population have naturally red hair - caused by a mutation in the gene mc1r. The resulting change in the protein it controls causes those who have this gene mutation to carry pheomelanin instead of the dark melanin in their skin, hair and eyes. This gives them much more sensitive, light colored skin and, in many case, lots of freckles.
The researchers behind the new discovery state that one percent of the Neanderthals in Europe had red hair - and it was definitely not dyed. The researchers tracked down the Neanderthals' hair color by means of genetic analysis: first, they attempted to multiply a piece of the mc1r gene from an extract of Neanderthal DNA. In doing so, they found a variant that has never been observed in modern humans.
Thanks to a series of complex tests, the molecular biologists were able to rule out the chance that the experimental samples containing the variant may have been contaminated with modern human DNA, or were a random result caused by damaged DNA or PCR errors (PCR, or polymerase chain reaction, is a method of multiplying DNA).
Functional tests then showed that this variant is much less active than the normal human variant.
"Gene variants with similarly reduced activity are also known in modern man - although they are a result of other mutations," says Michael Hofreiter. "In people, they lead to red-colored hair. We can therefore assume that part of the Neanderthal population may have had red or light colored hair and possibly even lighter colored skin," according to the paleoanthropologist.
Whether red hair in Neanderthals was considered particularly erotic or more of a turnoff is, of course, something the scientists cannot say.
Article: Carles Lalueza-Fox, Holger Rompler, Michael Hofreiter et al. "A melanocortin 1 receptor allele suggests varying pigmentation among Neanderthals", Science, October 25, 2007