(no subject)

[mari4212]

This is just a question that's been bugging me for a while, and given the amount of Harry Potter fans on my flist, where better to bring it up?

Okay, so in the books we're given three basic categories for wizarding birth. There are pure-bloods, half-bloods, and Muggleborn. Of the three, Muggleborn is the easiest to define, as a person born of two non-magical parents. Purebloods are also relatively easy to define, they're children born from families that have been magical for several generations. But how do you define halfbloods? I mean, we've got situations where one parent is magical and the other is a Muggle, and we've got Harry, whose parents both were magical, but Lily was a Muggleborn, and he's still technically a half-blood. Presumably, if two Muggleborns marry, their children are also considered halfbloods.

But where does it end? How long does it take for a wizarding lineage to turn from half-blooded to pure-blooded, if they continuously marry others who are magical? Ideas anyone? Bueller?

Comments

[ishie]

My first thought was that it might be similar to American attitudes toward mixed heritage, ie the distinction between mulatto, quadroon, octoroon, etc, being based on the number of non-white ancestors in one's direct family line.

On further reflection, though, I doubt that JKR's actually put that much thought into it. It seems more like a distinction that's made (half-blood v pureblood) by people who care about such things as a measure of a person's worth, and as such, one would remain a non-pureblood for as long as they couldn't cover up any "unsavory" ancestors.

[million-moments.livejournal.com]

I think the general idea is if your not pure blood, and your not muggle born, your half blood. Cause they do refer to Harry as half-blood in the books.

Wizarding genetics

[glacierscout.livejournal.com]

I don't think that JKR actually put much thought into the basis of magic, but it mioght be possible to solve it as a genetics problem. The key to the analysis is squibs, non-magical children of wizarding parents.

Assume that magic is a recessive trait on a non-sex-linked chromosome. Let M stand for the non-magical gene, and m stand for the magical gene. There are three possible combinations:

MM - completely non-magical (Muggle)
Mm - non-magical but carries a magical gene (Squib)
mm - magical ("pureblood")

There are six different pairings possible

MM - MM Muggle-Muggle, result in all muggles
Mm - Mm Squib - Squib, result in 1/4 MM, 2/4 Mm, 1/4 mm
mm - mm magical-magical, result in all magical

MM - mm Muggle - magical, all are Mm squibs
Mm - mm Squib - magical, 2/4 Mm squibs, 2/4 mm magical
MM - Mm Muggle - squib 2/4 MM muggle, 2/4 Mm squibs

Five conclusions:

1) Purebloods are partly right to be concerned about bloodlines, because magic is recessive, and marrying muggles or squibs will result in non-magical children. (see conclusion 4)

2) There are a lot more squibs than we expect. However, since they will be ostracized in the wizarding world, within 1 or 2 generations, they will pass as Muggles. The recessive trait will still be passed along.

3) There's no such thing as a "half-blood" or "Muggle-born". If two squibs, passing as Muggles marry, 1/4 of their children will be magical, and readmitted to the magical world. However, they will be "pureblooded" due to the recessive nature of the magical gene. Lily Potter's parents and Hermione's parents are all squibs passing as muggles, but both ladies are mm magicians. If they marry a wizard and have children, their children will be "pureblooded" wizards and witches too. Tom Riddle is the son of an mm witch and a Mm squib father, and is pureblooded too.

4 Therefore, the "pureblood" prejudice of Salazar Slytherin and his follwers in the modern world is wrong. So long as magical witches and wizards marry, their children will be magical too.

5 Squibs are rare in the wizarding world, and may be the result of witches cheating on their magical husbands. Squibs in the Muggle world may also be the result of male wizards fooling around.

More complicated schemes are also possible using a more complex inheiritance pattern, but this one will probably do.

Re: Wizarding genetics

[mari4212.livejournal.com]

That's interesting, Dad, but I was looking for a sociological perspective, not a biological one. ie, what makes a half-blood a half-blood in wizarding society. It's sort of like the fact that biologically, there are no actual races amoung humans, but socially there are.

[mari4212.livejournal.com]

Sure. I was just trying to define where the switch is made from half-blood to pure blood.

Re: Wizarding genetics

[glacierscout.livejournal.com]

That's going to vary from house to house. Slytherins, especially the current generation will never accept anyone as a full-blooded wizard or witch, so long as there is a trace of "halfblooded" in their lineage. The other houses seem to have no issue with bloodlines at all. Gryffindor especially has no problems with Hermione ("Muggleborn") or Lily (half-blooded) or even Harry (3/4 blooded?). We don't see as much from the other houses, but their reaction to Harry and Hermione (especially in OotP) seems to be respect for their abilities, whatever their bloodlines.

Biology does matter too - read Katharine Kurtz on the genetic aspects of Deyniness.

[cat-mcdougall.livejournal.com]

Actually, I think that there have to be 4-5 generations of direct magical descent before they are considered 'pureblood' on both sides. I might be wrong about that... But I think JKR put it in, one of her interviews or something like that. *shrugs*

Re: Wizarding genetics

[cat-mcdougall.livejournal.com]

Lily was muggleborn. And James was pureblooded, and HArry is a half-blood.

[skirmish-of-wit.livejournal.com]

In one of the interviews, JKR said that the negative attitudes about genetics were based on those in Nazi Germany, which went back to the grandparents. Thus, Harry is a halfblood because his maternal grandparents were Muggles, but Harry's own children (assuming he marries Ginny) will be considered purebloods, since their grandparents are all magical.

[skirmish-of-wit.livejournal.com]

er... that's not phrased very clearly... I hope it made sense.

[skirmish-of-wit.livejournal.com]

Sorry for the spam! Just one more thing. The term "halfblood" must cover more than just people who are literally half-and-half, since both Harry and Tom Riddle are described as halfbloods, even though Lily was a witch and Tom Riddle Sr. was a Muggle. So the term "halfblood," then, must refer to those with 1-3 Muggle grandparents. (Correct me if my logic is faulty!)

Re: Wizarding genetics

[glacierscout.livejournal.com]

Sorry. My goof in the second post. In my original one, i got Lily correct as so-called Muggleborn, but really a completely magical witch.

Nobility

[elvisvf101.livejournal.com]

Technically, I think there is a genetic point at which fractions drop in terms of bloodlines from a biological and geneological perspective. But I don't think that necessarily applies in this case.

The larger question, when does one go from half-blood to pure-blood. That is a societal question. And, in many cases, it's a retelling of the real question that is at the heart of the books:

Who are you? Are you who other people tell you you are, or are you who you choose to be?

The (societal) nature of a pure-blood is that it is simply who you are. You can not become pure-blood. You either are, or you aren't. Society will ultimately decide whether you are pure blood or not. OTHERS define who you are.

It's an age old type thing, old money vs. new money, etc. etc. etc.

The next question is, what does it matter? What does being a pure-blood do for you. This is another age old question. Are you simply what you are born to be, or are you what you choose to be.

This is the heart of all of JKR's writing, in my humble opinion. Harry has a destiny, but he also chooses to act. There is a prophecy that only came true because Voldemort chose to believe it. And he only believed it because he thought he was bound to it already.

There is a connection there to bloodlines. Are you what your blood tells you you are (if so, should Filch be summarily executed for being a squib, or Hermione for being a muggleborn witch?) or can you be what you choose (people who choose include Harry (defying the prophecy), Tonks and Sirius (defying their family) and Lupin (defying societal prejudices).

So, of course, the answer to your question is 42.