wizards & genetics

[heidi tandy]

No: HPFGUIDX 409

> But I think any magical gene would have to be recessive.  If 
> it weren't, it
> would be impossible to get a magical child from two Muggle 
> parents.  If M
> is recessive, then both parents could be mM and still be 
> Muggles, but their
> child would have a 1-in-4 chance of being MM and therefore a 
wizard, a
> 1-in-2 chance of being mM and a carrier themselves, or a 
> 1-in-4 chance of
> being mm and neither a wizard nor a carrier.  Since everyone in the
> wizarding world would have to be MM, then they'd have all 
> magical children.
> This does not explain how wizards could have non-magical 
> children, though.
> It ought to be impossible if magic is recessive...however, almost no
> traits are coded for by a single gene.

I am no scientist, but I have a possible explanaiton for this - since 
things aren't coded by a single gene, then maybe there is a gene for 
magic, which is recessive, and another series of genes which block 
the use of magic even by a person who has inherited genes for magic 
from both parents - when the whole series is present, you have a 
squib, but if only 1 of the 5? 6? genes in the series is missing, 
then the "magic" gene isn't blocked, and voila, you have awitch or 
wizard!