Hermione's Friends; genes

[macloudt at yahoo.co.uk]

No: HPFGUIDX 26750


 Magic, I agree, has to be a dominant trait - otherwise, it's true,
> you could never have muggle-born witches & wizards because the 
Magic traits
> would be over- ridden by the Muggle traits. 
> However, if it was only one gene, there would be *no* squibs 
(absent genetic
> mutations), because all Magic parents would pass their genes onto 
their
> ofspring. But if it is more than one gene, and if you have to have, 
say 3 of
> the 5 to NOT be a squib, then the absence of one of those genes in 
each
> parent would result in a Squib offspring BUT would allow the Squib 
to be a
> parent of a Magic baby.

'Fraid I have to be anal retentive here...if I recall my grade 9 
biology correctly, it IS possible for a trait to derive from a 
recessive gene *if* both parents carry that recessive gene.  This is 
how, for example, 2 brown-eyed (dominant) parents can have a blue-eyed
(recessive) child.  So there could be *thousands* (if not more) 
Muggles walking around with recessive magic genes, ready to pass them 
on to their child in blissful ignorance. There could be many 
generations of Muggles carrying this gene before the right people 
mate and produce a witch/wizard.  

As you say, though, there must be more than one gene involved, or 
there would be no Squibs as far as I can see.

Any biologists/geneticists out there who can improve upon my grade 9 
biology?

Mary Ann
(who dropped science before she could take chemistry, thus saving the 
school from certain catastrophe)