Magical genetics

[jodel at aol.com]

No: HPFGUIDX 47419

I'm on three other lists where this subject crops up fom time to time, some 
of the suggestions from the last round of discussion make some sense here as 
well.

Catlady says;

>>Since every witch and wizard is homozygous for MAGIC, those are the only 
genes they can pass on to their children -- no wonder Squibs are rare! I 
think 'rare' like 'one in a generation'. Because either they DO have the 
GENES for Magic but their magic was broken by something like a birth defect, 
or one of their parents isn't really their parent. Implication: Momma Witch 
was cheating on Papa Wizard with a MUGGLE!<<

One of the most recent postulations on one of my lists is that since it is 
obvious that everybody's magic is different from nearly everybody else's, 
there has to be more than one "magical" gene in play. And the probability is 
that most, even if not all, of these probably are recessive, since once 
introduced, a recessive can hang around for aeons. Quite a few magical genes 
may activate even if not doubled, however. These may only require that the 
gene from the other parent give neutral instructions rather than present an 
outright conflict.

It was suggested that there are probably at least a couple of dozen such 
genes for magic, and that a subject must carry at least a minimum number of 
them (say, 8-10) before they are psychicly active enough to produce or 
channel magic, themselves. A subject might carry a LOT more than the minimum, 
however. Which would explain how some wizard/Muggle crosses consistently 
produce magical offspring while others may not.

Another postulation was that in Rowling's world, magical genes are fairly 
widely spread in the Muggle population. That perhaps half the general 
population is carrying at least 1 or 2 magical genes. Muggle-born magical 
children result when two of these "near wizards" mate, and that once such a 
pairing has produced one magical child, the odds of their producing others 
are much higher. When the two "near wizards" carry gene sets that do not 
overlap, the resulting child may have as broad a range of magical 
capabilities as some of the best purebloods. 

And, rarely, in the case of two wizards with narrow-ranged gene sets, if 
something goes wrong, they might manage to produce a Squib. A sugestion that 
chromosonal damage as a result of curse damage or exposure to some dangerous 
magical process might be the cause of this. This possibility would also 
account for why some people with a normal to high amount of magical energy 
might still show a pronounced weakness in one or another area (example; 
Neville Longbottom shows a pronounced weakness in both Potions AND -- by his 
own account -- Transfiguration, leading one to suspect that he may not have 
inherited a full set of the genes necessary to producing "change" magic. His 
father's profession as an Auror would certainly have put him in harm's way 
for catching curses. Neville's difficulty in focusing his magic is probably 
due to some other cause than genetic damage, however.)

-JOdel