In my family, while neither of my parents have red hair, my brother and both my grandmothers on my mom and dad’s side do. It is interesting to think that I may be carrying a gene for this red hair, and could possibly pass it down, because ginger hair is somewhat of an oddity. It is commonly suggested that only around 1 to 2 percent of the world population (70 to 140 million people) have red hair (Barnes, 2013). On Wednesday, June 13th, I learned even more about my family’s redhead heritage.
On that Wednesday our class went on an outing to the Musee de l’Homme and looked at the Neanderthal exhibit. The exhibit introduced the now extinct species Homo neanderthalensis. The museum had exhibits showcasing the physical differences between the Neanderthals and humans, such as their shorter and stockier build, and lack of chin and sloped forehead. However, what I thought was most interesting was the fact that these Neanderthals, who were living around 430,000 years ago, had either brown or red hair. In fact, all humans who have red hair, or the red hair gene, have an ancestor that was a Neanderthal! Homo sapiens and Neanderthals co-existed in Euroasia all those years ago, and would sometimes cross-breed with one another, resulting now in modern families, like mine.
The fact that red hair comes from Neanderthals led to me to start thinking about certain characteristics redheads are known for. In a Psychobiology class the teacher mentioned that redheads have a higher tolerance to pain. Somehow the neural networks of pain reception are altered so that redheads have a higher baseline pain tolerance compared to those who do not posses the redhead MCIR variant (Mogil, et al., 2005). A study was done and it was suggested that this melanocortin-1 receptor, which is involved in skin/hair pigmentation and immunomodulation, can also influence acute pain and opioid analgesia (Rees, et al, 1999; Mogil, et al., 2005). Mogil, et al., (2005) found that the MCIR gene is linked to the efficacy of the m-opioid M6G, and that there is an observed greater M6G induced analgesic responses in redheads.
I think it is interesting that it was the Neanderthals that originally possessed the red hair gene, and that this gene is linked to higher pain tolerance. The Neanderthals lived in extreme conditions and most likely experienced more pain in their day to day lives, so it makes sense that this gene came from them. I also feel a personal link to the Neanderthals, knowing that we are related somewhere very far down my ancestral line!
References
Barnes H., (October, 2013) How many redheads are there in the world? BBC News. Accessed at https://www.bbc.com/news/magazine-24331615.
Mogil S., Ritchie J., Smith S.B., Strasburg K., Kaplan L., Wallace M.R., Romberg R.R., Bijl H., Sarton E.Y., Fillingim R.B., Dahan A., (2005) Melanocortin-1 receptor gene variants affect pain and m-opioid analgesia in mice and humans. J Med Genet, 42: 583–587.
Rees J.L., Birch-Machin M., Flanagan N., Healy E., Phillips S., Todd C., (1999) Genetic studies of the human melanocortin-1 receptor. Ann N Y Acad Sci, 885: 134–42.