Freshly Baked Science
Love Is In The Hair
4th June 2018
Unless you have been living under a rock for the past 6 months, I’m sure you are aware of the Royal Wedding between Prince Harry and Meghan Markle. We figured this would be the perfect opportunity to discuss the inheritance of ginger hair. After all, there is no subject more important than the possible hair colour of their non-existent baby!
Let's dive right into the genetics (it’s not as scary as it sounds, I promise)!
At its simplest level, hair colour is determined by a gene called MC1R. When fully active, MC1R produces a lot of dark pigment, resulting in black or dark brown hair. When inactive, MC1R produces a small amount of light pigment, resulting in blonde hair.
There are a few changes (or mutations) which can occur in MC1R and are collectively known as the ‘red gene’, and as the name suggests results in red hair. The specific change (or mutation) to MC1R causes a range of shades from strawberry blonde to auburn. These colours are produced when there is much more light pigment than dark pigment.
Every human inherits two copies of every gene; one from their mother and one from their father. A person with ginger hair will have 2 copies of the 'red gene'. A person with brown hair could either have 2 copies of the ‘brown gene’, or 1 ‘brown gene’ and 1 ‘red gene’. This is possible because the ‘red gene’ requires 2 copies in order for the hair to be red, so when there is only one, the other gene will dominate.
When a person, with a hair colour which is not red, has a copy of the 'red gene’, they are known as a carrier. Genes are passed to offspring at random, so there is an equal chance of giving the offspring either the ‘red gene’ or their hair colour gene.
This means that 2 brown-haired carriers could have a red-headed child if they both passed the ‘red gene’, that they are carrying, to the child. This has a 25% chance of happening. If a redhead and a brown-haired carrier had a child, they have a 50% chance of having a red-haired child. However, a redhead and a brown-haired person will have carrier offspring, but can’t have red-haired children.
Does this gene have an effect on anything else?
Unfortunately, having the ‘red gene’ does not automatically make people extremely talented acoustic singers…Ed Sheeran must have just got lucky! It is, however, usually associated with pale skin, freckles and sensitivity to UV light (not quite as desirable). Despite the sensitivity to UV light leaving gingers struggling with sunburn in intense sunlight, it does have its perks, as the body is able to produce more vitamin D in lower light levels.
This means that redheads are usually better suited to cooler climates, with less intense sunlight. Due to this, natural selection has left redheads being most frequently found in Western and Northern Europe, where sunlight isn’t as intense as places like Australia and Africa.
So what colour hair will Prince Harry and Meghan Markle’s non-existent baby have?
I think we can safely say that Prince Harry’s fiery head of hair suggests that he has 2 copies of the 'red gene’, so he will pass one of those to his children. Meghan, on the other hand, could either be a carrier or not a carrier. However, given her ancestry, it is more likely that she will not be a carrier. If this is the case, then their children will not have red hair, however, they will be ‘red gene’ carriers. This means that there is a chance that their grandchildren will have Harry’s ginger locks!
Do you have ginger hair? Take a look at your parents and grandparents hair colour and see if you can work out where the genes came from! Tweet us (@magazinewonk) with the hashtag #mygingergenes