Wizarding Genetics

This is a bit of a throwaway to explain my concept of how being a witch or wizard is inherited to cover both muggleborn and squibs; and too those whose magic does not flow properly.

I have seen a suggestion in one story of those of wizarding blood having a triple helix to identify them as different. It worked in context for the story but I generally reject the concept for two reasons.

1. Because if wizards have accidents and are either examined by muggle doctors or their blood is taken from the scene of a crime it rather gives the game away.

2. In inheritance, one zygote will have the double strand, one the single. This makes the new foetus 50% likely to be a wizard with one strand each of double and single making the triple; 25% unviable with a quadruple strand; and 25% presumably squibs since that have a normal double helix. There is no suggestion that the incidence of squibs is as much as one in three of live births.

But I did like the way it was used in the story so this isn't a flame of the concept just a discussion of logical inconsistency.

MY IDEAS

I see inheritance as being carried on several genes rather like skin colour, which is determined by six separate genes; which is how come two people of African heritage can have an apparently white baby and vice versa providing the heritance is carried at some point. The number of genes for pigmentation determine the darkness of the skin.

Even so, wizarding genes come as a set of six; and it takes four of them to be active wizarding genes in order to have a wizard who will show up in The Book as eligible for Hogwarts.

Naturally wizards are not always good boys and their genes lurk in the general populace through this; and when two muggles marry who have a sufficient array of wizarding markers between them, then there is the likelihood of a muggleborn child. And it does not follow that all their children are magically active.

Take Lily and Petunia Evans; Lily, highly talented; Petunia a muggle. Suppose each of their parents had three wizarding genes each; and Lily gets lucky and gets three from each, giving her six making her very capable. Petunia could have ended up with three genes from each that were NOT active, making her the most mugglish of muggles with six inactive genes, though I suspect she has about three active genes, enough to thirst for more.

[a thought; does Vernon fear magic so much because he has six inactive genes – or because he has four or more active and scared himself doing uncontrolled magic in his early years and deliberately blocked out on it? I shall address blocking shortly re Ariana and Neville]

I further contend that each of the six markers might be more or less able to function at full activity for any one of a number of reasons; and one of the reasons that may stunt their activity is inbreeding. I cite the Gaunts who were not of the most powerful by the time Marvolo, Morfin and Merope were their sole line. A genetic heritable defect might be to blame or just a reaction to too similar a heritance causing hormonal damage to the genes.

Squibs have three or more damaged genes stunting their ability. They have been affected in the womb either by environmental factors [certain potions perhaps or illness on the part of the mother] or just by genetic accident. It seems to be a relatively common genetic accident, as trisomy 21 is in muggles [Down's Syndrome].

Similarly some genes may operate at a higher level of efficiency making he possessor a more powerful wizard; evolution in action.

Blocking

Ariana and Neville have both blocked their own magical powers as a result of trauma. I contend that this is a result of the release of a hormone as a response to strong fear to suppress the active genes. This would have originally have been a survival mechanism to prevent very young wizards from displaying magic in an inappropriate environment but has possibly mutated to become a potentially harmful effect. By losing stress about performing magic the condition can be improved and the hormone no longer released as we can see Neville managing to do. Ariana was abused by not being permitted treatment in St Mungo's and by having such a big thing made about her blocking.

Since magic is controlled by more than one gene of more than one level of response this accounts for the incidence of some very powerful pure bred AND muggleborn witches and wizards and for those who blow up cauldrons, cannot get a matchstick to turn into a needle and drop everything they levitate. I would hypothesise also that if there are one or two damaged genes, not enough to make a squib, this might be heritable. Indeed this would give a good reason for the low ability of the Gaunts especially if they are inbred and so magnified the effect of one or more damaged genes. As Merope is also clearly blocking because she fears her father this makes her look more like a squib to him.

I would further contend that three active genes mean that a muggle may be capable of limited magic with patient training and will certainly have enough magical energy to form the necessary catalyst to brew potions; because the aura of magic is what is required to turn a poisonous mess into a potion. Which means that many a squib might also be able to brew potions and learn some limited magic if not totally written off by their parents. Unfortunately squibs do not seem to be treated very well by society and probably are thus written off.

Generally speaking it is not worth training those with less than four active genes and so nobody bothers; which means they are out there ready to produce muggleborn children. And I also contend that these are the ones who can see more readily things that have been disillusioned. And they probably do not talk about it because when they have been ticked off as a small child for mentioning the funny little man with long feet and fingers because their parents see him as faintly foreign, perhaps, and do not want to be accused of bringing up a racist child either they fool themselves into seeing what they are supposed to see, or just keep shut about it.

I'm not a biologist, I never went further than a wild module in biochemistry in my freshman year which I ended up on almost by accident [long story] though I enjoyed it!. However I have read widely in genetics, and did a bit of intensive research in Tortora and Grabowski which I reference. It's a jolly good book and was a seminal work for a Biology degree where I was at Uni.