In any kids' book about quaternary megafauna you will find a picture of a woolly mammoth. I can almost guarantee that the wool on that woolly mammoth will be some shade of red, from copper-penny red through rich auburn to moody chestnut. The reason that artists always portray mammoths as red-heads, aside from the fact that red-heads are just so darned good looking, is that we have actual hair from woolly mammoths and it is red. This would seem to preclude any questions about the color of mammoths and yet it does not.
Hair is almost clear with a core that contains particles of pigment and bubbles of air. Black hair and red hair in humans use the same pigment. Solid pigment produces black hair and specks of pigment and air bubbles show up as various shades of red. Several processes can turn black hair red. Malnutrition can reduce the production of pigment. In many parts of the world where black hair is the norm, red hair was a sign of ill health, most often associated with famine. When red-headed explorers and missionaries arrived in central Africa, the Pacific islands, and southeast Asia, they were often pitied and assumed to be ill.
Certain chemical processes can also turn black hair red. African and Asian Americans can achieve many shades of red through light bleaching. More significantly for mammoths, chemicals in the ground can turn black hair red after burial. This probably explains the mysterious presence of red-headed mummies all over the world. It might also explain why mammoth hair is always red. That doesn't mean the mammoths weren't red to begin with. They might have been red and they might have started with a darker color and become red.
Today, the journal Science has news of research the gives us a few more clues about mammoth color, but doesn't settle the issue. Evolutionary biologists at the Max Planck Institute have decoded part of the genetic code of mammoths and located a gene (Mc1r) which controls hair color.
In humans, reduced activity of the Mc1r gene causes red hair, while in dogs, mice and horses it results in yellow hair.
Using ancient DNA extracted from the excavated mammoth bone, the international team of researchers were able to look at the variations in copies of the Mc1r gene.
Dr Michael Hofreiter, an author on the paper and an evolutionary biologist from the Max Planck Institute for Evolutionary Anthropology, Germany, said analysis revealed two different versions of the gene were present - a fully active and a partially active version.
The researchers propose that hair coloration in mammoths is likely to have been determined in the same way as in present-day mammals.
This means that mammoths with one copy of the active gene and one of the partially active gene would have had dark coats - most likely dark brown or black.
While mammoths with two copies of the inactive gene would have had paler coats - possibly blond or ginger.
What this tells us is that mammoths came in a variety of colors, light and dark, but, until we know more, we can't say what those colors were. It might have been brown to blonde or black to red. Like cats in the dark, all dead mammoths are the same color.
* And most kids these days do have books about quaternary megafauna. This is quite a change from my day when all we had were anthropomorphic steam shovels and home invasion by anarchistic felines. It's not fair, man.