Wizards, Muggles, and Genetics (long)

[huntergreen_3]

No: HPFGUIDX 119744


charme wrote:
>> The one other question I have is if in Muggles magic is the 
RECESSIVE gene, and non magic is the DOMINATE one (the opposite of 
what wizards are supposed to have), and what a fine kettle of potion 
that would be to figure out....
[snip]
While I used the analogy of blood type to make my point, I could have 
complicated it more by using eye color genetics which is far more 
complex. For example, for a child to be born with blue eyes, it means 
both genes with all 4 alleles (alleles are variations of genes and 
for this illustration, 2 alleles to a gene) for eye color must be all 
blue as blue is a completely recessive trait. Brown swamps blue, and 
green will swamp blue too. <<

HunterGreen:
But 2 brown eyed parents can have a blue-eyed child, but not the 
other way around. It might be as you say charme, that the magical 
gene is recessive in muggles and dominant in wizards. 

Dungrollin:
>> What I'd like to know is what you call the non-magic offspring of
a witch/wizard and a Muggle. Are they Squibs, or Muggles? <<

charme:
>>Oh this is such a great question! :) It's also exemplifies exactly 
what I was theorizing about Squibs and Muggles: are they *really* that
different???<<

HunterGreen:
I think they have to be. From the evidence we have in the books and 
what she said on the site, a squib is a very rare defect, and a 
muggleborn wizard is somewhat common. 
JKR said that "A Squib is almost the opposite of a Muggle-born 
wizard: he or she is a non-magical person born to at least one 
magical parent. Squibs are rare; magic is a dominant and resilient 
gene."
So if a witch/wizard had a non-magical baby they would be a squib. I 
think what JKR might mean by "dominant" here is that if two 
muggleborn wizards had a baby their chances of having a squib are the 
same as two pureblood wizards. Meaning that the magical gene in its 
activated form will always beat out any muggle genes, except in rare 
cases of squibs. 
It makes me wonder if *every* generation would still have the same 
chance of getting the wizard gene (if every generation married a 
muggle), or if it would get less likely with time. It must. Otherwise 
how do you explain the large number (25%) of the Hogwarts populace 
that are muggleborn? And if it is a strange occurence not based on 
the genes of the parents then its an amazing coincidence that kids 
like Colin and Dennis are *both* muggleborns (unless of course one of 
their parents is a wizard or a squib, I suppose).

Now that leads me to another question, are squib genes the same as 
magic genes when it comes to having a baby? Or are they like muggle 
genes? I used to think they were, but since it is the non-activated 
side of the magic gene, perhaps it becomes recessive.