Wizard Genetics

I’m on the 5th Harry Potter novel, and Mrs VF is waiting for numbers 6 and 7 to arrive. We rented the first four movies and found that they were a pretty good compression of the books. I’m not sure that they would make as much sense if you hadn’t read the books.

I have a theory about how a child of Muggles might turn out to be a Wizard or how a child of magic folks might end up a Squib. You are a Wizard if you have two instances of a recessive gene w. The w gene might pass through many generations of Muggles without being expressed because you need a pair of them to make a Wizard. The dominant Muggle gene M at the same locus trumps the w when combined with it. A Muggle could have MM or Mw, whereas a Wizard must have ww.

There is a second gene that governs the ability to do magic. Let’s call it A. It is tied to the w gene such that you have to be a Wizard in order for A to be expressed. You might have another variant of the gene, lets call it a, that confers no magical ability. A Wizard with two a’s would be a Squib. A Wizard with one A would be an ordinary specimen, whereas a Wizard with two A’s would be more powerful. A Muggle with A’s would not have any magical ability.

To summarize:

ww/AA= heap powerful wizard
ww/Aa= regular Wizard
ww/AA= Squib
wM/??= Muggle
MM/??= Muggle