Did Neanderthals Have Red Hair? Skin, Hair and Eyes

In 2007, a team led by Carles Lalueza-Fox read a short stretch of one pigment gene from two Neanderthal bones: one from El Sidrón cave in northern Spain, one from Monti Lessini in northern Italy. Both carried a change no one had seen before. It swaps a single amino acid in the MC1R receptor, and in lab tests it weakens the receptor in the same way the variants behind modern red hair do.

That one result answers the question did Neanderthals have red hair better than a century of artists' guesses. The answer is "some probably did", but the details are more interesting than the headline.

Why MC1R decides red hair

Hair and skin colour come from two kinds of melanin. Eumelanin is dark brown to black. Pheomelanin is red-yellow. The MC1R receptor, which sits on pigment cells, acts as the switch between them. When it works well, cells make mostly dark eumelanin. When it is weakened, they fall back on pheomelanin, and the result is red hair, freckles and pale skin that burns easily.

About 1–2% of people worldwide have red hair, most often in northwest Europe. Nearly all of them carry two weakened copies of MC1R, one from each parent. Common variants include R151C, R160W and D294H. One weakened copy usually changes skin and freckling without making the hair fully red.

That last point matters for Neanderthals. Finding a weakened MC1R allele tells you the trait was possible. It does not tell you how many individuals carried two copies and actually had red hair.

Did Neanderthals have red hair? The R307G variant

The Neanderthal mutation swaps arginine for glycine at position 307 of the receptor, so it is written R307G. Lalueza-Fox and colleagues screened about 3,700 living people and found no one carrying it. They then inserted the Neanderthal version into cultured cells. It responded to its activating hormone much less strongly than the normal receptor, a partial loss of function like that of modern red-hair variants.

The authors estimated that at least 1% of Neanderthals carried two copies and so would have had reduced pigmentation. The real share could have been higher. With only two individuals typed, nobody can pin it down.

The key finding is not "Neanderthals were redheads." It is that the Neanderthal lineage weakened the same gene by a different mutation. Two human lineages arrived at similar colouring separately. Biologists call that convergent evolution.

What full Neanderthal genomes add

Since 2010, researchers have sequenced several Neanderthal genomes, including high-quality ones from Denisova Cave and Chagyrskaya Cave in Siberia and Vindija Cave in Croatia. Predicting appearance from them is harder than it sounds. Pigmentation depends on dozens of genes, and the prediction tools are calibrated on living Europeans, not on a species that split from our line more than half a million years ago.

A more indirect route has proved useful: studying the Neanderthal DNA that survives in us. About 2% of the genome of people with non-African ancestry comes from Neanderthals (see how much Neanderthal DNA you carry). In 2014, Sriram Sankararaman and colleagues found that this inherited DNA clusters in genes for keratin, the protein of hair and the skin's outer layer. That hints that some Neanderthal skin and hair genes were useful to modern humans arriving in cold Eurasia.

In 2017, Michael Dannemann and Janet Kelso tested Neanderthal variants against traits recorded for more than 100,000 people in the UK Biobank. Neanderthal alleles were linked to skin tone, hair colour, tanning ability and sunburn. Some were linked to lighter colouring and others to darker. The simplest reading is that Neanderthals themselves varied, much as people do today.

Why pale skin at high latitudes?

The usual explanation is vitamin D. Skin makes vitamin D when ultraviolet B light strikes it, and UVB is weak in winter far from the equator. Lighter skin lets more UVB through, so selection at high latitudes tends to favour it. Near the equator, dark skin protects against UV damage and folate loss. Our article on the evolution of human skin colour covers this in depth.

Neanderthals lived in western Eurasia for several hundred thousand years, long enough for that pressure to act. Modern Europeans show how quickly the process can run. Ancient genomes analysed by Iain Mathieson and colleagues in 2015 show that the light-skin variants of SLC24A5 and SLC45A2 rose sharply in Europe only in the last 8,000 years or so. That is why Cheddar Man, a Briton who lived about 10,000 years ago, is predicted to have had dark skin and pale eyes.

The vitamin D hypothesis is widely accepted but not proven for every case. Diet matters too: people who eat a lot of fish or liver get vitamin D from food. Sexual selection and genetic drift may also have shaped colouring in small populations. Treat "pale because of the sun" as the leading explanation, not a settled law.

How reconstructions have changed

Early 20th-century illustrations, many based on Marcellin Boule's study of the La Chapelle-aux-Saints skeleton, show stooped, hairy, dark figures. Boule's posture errors were corrected in the 1950s, but the dark, shaggy image lasted much longer.

After 2007, many museum models began to show fair-skinned Neanderthals, some with auburn or red hair. That is defensible for some individuals. It becomes misleading when one look stands in for a whole species that lived from Gibraltar to the Altai Mountains. A Neanderthal in Mediterranean Iberia 120,000 years ago and one in Siberia 50,000 years ago belonged to populations separated by thousands of kilometres and tens of thousands of years.

What we still cannot say

• How common red hair was. Two typed individuals are not a population sample.
• Eye colour. The main blue-eye variant in living Europeans, near the HERC2 and OCA2 genes, arose in modern humans. Neanderthal eye colour remains an open question.
• Body hair. No gene test tells us how hairy Neanderthals were. Our piece on how humans lost their body hair explains why that trait is hard to read from DNA.

Why it matters

The red-hair question shows how ancient DNA turns extinct people from artistic guesswork into testable biology. It also shows convergent evolution inside our own family. Similar environments pushed Neanderthals and modern humans toward similar traits through different mutations. Some of the Neanderthal pigment variants live on in people today. To see where Neanderthals sit relative to us, explore the interactive family tree or compare Homo sapiens and Neanderthals side by side.