Two “pure blood” Wizards almost always produce a Wizard (Malfoys, Blacks, Weasleys) though they can produce a Squib (Filch).
A Wizard and a Muggleborn Wizard usually produce a Wizard (Harry)
A Wizard and a Muggle can produce a Wizard (Voldemort)
Two Muggles will usually produce a Muggle, but they can produce a Wizard (Hermione, Lily)
Supposedly Squibs are the same as Muggles except in their rearing and exposure to Magic.
So would it be fair to say that Wizardry is the dominant gene and Muggle is the recessive? And that Muggles are most likely descended from Wizards or the other way around?
I’m trying to recall if the Brothers Dumbledore are pure-bloods or part Muggle- has it ever said?
Yep, magical ability is apparently a dominant gene. Rowling even says so on her website.
As for who is descended from whom, I’d say that wizards came from Muggles. There really aren’t that many magical folks around (Rowling says that if you gathered all of the wizards and witches in England together, you could fill a decently large town, but that’s about it) and the magical community is constantly borrowing inventions from Muggle society and marrying Muggles, so I say that they’re definitly the offshoot group.
It may be worth noting that it is revealed in OotP that squibs can see dementors, while muggles cannot. Whether this is because of early exposure to magic in some way, or due to inherent differences between squibs and muggles is unclear. Squibs may only be impaired in their ability to access and control magic, not in their ability to perceive magical phenomena. In that case, squibs would have the “wizarding” gene or genes.
As Diceman says, the population distribution strongly suggests that wizards are the offshoot, particularly if the wizarding gene is dominant.
Hijacking my own thread, but I still have a suspicion that Petunia is a squib (and I think it’s more than cutesy naming that Filch’s cat is named “Mrs. Norris”).
Maybe Muggles are the offshoot. Population distribution would also have to depend on progeny, wouldn’t it? Most wizarding families strike me as unnaturally small – the Weasleys being the notable exception. Most of the unmarried wizards have no siblings or children, most married ones have one child. Maybe Wizards have superior breeding, but the mudbloods since time immemorial had them outbred.
Hmm…now I’m wondering about this. I don’t think it can be classical Mendelian inheritance. Suppose W is the gene that makes a wizard, w its allele, and that W is dominant.
In that case, a wizard can be WW or Ww, whereas a muggle can only be ww. There are 6 possible pairings: WW and WW, WW and Ww, WW and ww, Ww and Ww, Ww and ww, and ww and ww.
WW and WW can only produce a WW. WW and Ww can produce a WW or a Ww with equal probability. WW and ww can only produce Ww.
Ww and Ww can produce WW (1/4), Ww (1/2), or ww (1/4). Ww and ww can produce a Ww or ww with equal probability.
But ww and ww–a muggle/muggle pairing–can only produce ww. That means that under this model, two muggles can’t produce a wizard. Since that happens from time to time, that pretty much means that you’d need multiple genes for wizard skill.
Slight hi-jack:
One of the premises of the series is that magic folk keep the “Wizarding World” secret from the Muggles. But it’s also established in the series that pure-bred wizards are rare - most have Muggle relatives. Moreover, these Muggles - Hermoine’s parents, the Dursleys, etc - are aware of the existence of magic.
Well, if most wizards have Muggle relatives, and Hogwarts has been in existence for over a thousand years, and Hogwarts isn’t the only Wizarding School, wouldn’t that mean that over time the percentage of Muggles who are aware of the Wizarding World would approach 100%? How exactly do they keep this a secret?
Not true. The crazy cat lady squib was asked this by the court (so whether squibs can or not is not common knowledge) and said they could.
However, she could not describe the dementor very well. The implication was that she lied for Harry’s sake. She could certainly feel the dementor, but then, so could Harry’s muggle cousin.
ultrafilter you don’t actually need multiple genes, just a new mutation in the existing gene. There are several genetic disorders, both recessive and dominant, where new mutations make up a significant proportion of people with the abnormal gene. It is thus quite possible to suffer from a dominant genetic disorder even if neither of your parents has it.
Eg
Achondroplasia is a recessive gene, which is lethal in it’s homozyzous form, meaning people with Achondroplasia are hetereozygous for the gene.
However, most families with an Achondroplasic child do not have an Achondroplasic parent, and the child aquired the gene through a new mutation.
Not with the inheritance pattern you describe. There is no particular evidence one way or the other for dominance of one character over the other.
ultrafilter has the basic genetics right - if Wizardry is dominant, two Muggles will never produce a Wizard, barring a new mutation. Irishgirl is correct to point out that new mutations could account for Muggles sometimes producing Wizards even if they are homozygous reccessive. However, Muggleness could also be dominant, and the occasional non-Wizard produced by pureblood Wizards could be due to a reverse mutation.
No way to tell, really, without much more detailed information about lineages and inheritance patterns.
Since she says it is genetically related, we can shortly expect the HGP to allow everyone to be so. Soon, everyone will be a wizard, and Hogwarts will be nothing more than a dusty relic.
I call this the WoD problem. A friend of mine took White Wolf’s own numbers and found that the actual number of people who were supernatural considerably outnumbered lawyers, and those numbers did not include the normals who knew what was going on. His numbers basically mean that several of your friends and aquaintences were going to be vampires, werewolves, mages, gypsies, and whatnot. In other words, it would have to be the world’s biggest open secret.
It’s unclear whether she was vague because the Dementor is vaguely formed (and she was pretty upset and nervous both at the time and at the deposition) or because she was lying. Moreover, it would be a foolish and dangerous lie. I can’t see a society fo wizards with the capacity to experiment like that not having noticed at some point that Squibs could or could not see Dementors. And I doubt Dumbledore would have risked it, assuming, of course, that he had any other choice.
Sad to say it, but I don’t think she’s going to do anything interesting there. JKR is fairly inventive, but she’s damnably predictable, at least in the general direction a character will go.
Yep, JKR has said Petunia is a Muggle and not a Squib, but she’s hinted that there’s something else going on with her. From the Edinburgh Book Festival Q&A session:
Magic doesn’t really seem to work like either a dominant or a recessive gene, as far as I can tell – almost every child with at least one wizarding parent is magical, so it can’t be recessive, but if it were dominant there wouldn’t be any Muggle-born wizards. The general consensus on fan sites seems to be that there have to be multiple genes involved, and maybe some environmental factors (i.e. perhaps you have to be exposed to magic as a child for it to “kick in,” and even Muggle-borns might get exposed by accident, if they have wizard neighbors or something).
That’s a great link- thanks! I love this hint (about something non-genetic):
This would explain why Dumbledore is 150 years old (i.e he’s from Arizona where things live longer).
And of course this one:
It’s fairly obvious that Harry cannot live without Voldemort and vice versa, and there have been numerous comments on their resemblance. I think somehow a “merger” took place in the death spell that made them one and to kill one is to kill the other, though there’s no way she’ll have Harry commit suicide- perhaps Harry did die… hmmm… Phoenix… ah well
Mrs. Figg was certainly lying in her testimony. But not about her ability to see a dementor. Consider: When she arrived in the alley, she ordered Harry not to put his wand away, because “they might come back.” “They” who? The dementors, of course. Who told her that there had been dementors there? Nobody. She saw them being driven off by Harry’s Patronus. What she was lying about was witnessing the beginning of the attack. I’m fully confident that she witnessed the end.
BTW, what’s Arabella Figg’s maiden name, hmmm? And whatever became of Mr. Figg?