Were the Creevey Brothers Muggle-Borns?

[danajsparks.livejournal.com]

We have discussed before how Rowling seems to have "forgotten" in her later books that she originally intended for Colin Creevey to be a Muggle-born student. For one, it seems somewhat improbable that Colin and Dennis both turned out to be wizards if both of their parents were Muggles. For two, the fact that Professor McGonagall had to "chivvy" at least one Creevey out of the castle in chapter 31 of DH suggests that, despite the prohibition against Muggle-borns, the brothers were able to attend Hogwarts while Tom was in power... though it's possible that Colin, like Dean, was present for the final battle only because he had responded to Neville's alert on the DA coins.

However, it occurs to me that Colin's blood status was actually a bit ambiguous from the beginning.

What he told Harry in chapter 6 of COS is this:

I never knew all the odd stuff I could do was magic till I got the letter from Hogwarts. My dad’s a milkman, he couldn’t believe it either. So I’m taking loads of pictures to send home to him.

What Colin did not include in his introduction is any information about his mother. Thus, despite Colin's ignorance of magic, it's entirely possible that his mother was, in fact, a witch (or maybe a squb). If so, she would not have been the first witch to have hidden her magical abilities from her Muggle husband for as long as possible, nor do we know if she was even still in the picture by the time Colin received his invitation to Hogwarts.

Yes, Colin was petrified by the basilisk in COS, but that does not prove that he was a Muggle-born. It's possible, for instance, that he was simply in the wrong place at the wrong time. Furthermore, as far as we know, the only way to properly identify a Muggle-born is by investigating his or her family tree, and Diary!Tom could only know what Ginny knew or believed about the current student body.

Comments

[jodel-from-aol.livejournal.com]

Absolutely correct. The Creevy brothers could have been halfbloods. All we know for sure is that their father is not a wizard. (Actually, the idea that Mrs Creevy was no longer present by the time Colin was 11 would explain the situation very tidily.)

However, for quite a few years I believed that if a pair of apparent Muggles produced one magical child, the chances of producing another was exponentially higher. I am not altogether sure that this may not still be the case, but at the time I formulated that theory, I had not been given some further information on genetics, much of which may be due to the Human Genome Project which was barely a gleam in a scientist's eye when I was still in school. Information such as the fact that normal DNA appears to include strings and strings of "empty" genes which appear to contain no data, and could potentially be a perfectly reasonable place for harboring inheritable magical traits for the potential use of future generations.

I still flatly dicount Rowling's statements on magical inheritance since she seems to believe in a 'single-gene' theory where all magic is due to the inheritance of a single gene, despite the fact that her own story repeatedly gives us statements about "rare" magical gifts such as parseltongue, or the seer's gift, and the fact that different witches and wizards apparantly have magic of different strengths -- which is all incompatable with the view that all magic is tracable to a single gene. Particularly when you further muddle the issue by postulating non-human magical species which can cross-breed with human wizards and produce offspring which display their non-human parents' specific magical gifts.

Since that time however, I've refined my original theories a bit to postulate the Squib factor as a spontaneous mutation that disables the expression of magic. I am hypothesizing that with the Squib factor present, magic does not build up in and need to be expressed (in the unintentional magical breakthroughs common to juvenile wizards, certainly, but cannot be consiously channeled and projected either). And the Squib factor is a single gene, and it's dominant. If it is present, the offspring is a Squib. But, like all dominant genes, once it fails to be passed on, it's gone. Any magical traits lurking in the DNA are also inheritable, but they operate as recessives. Recessives can continue to propigate for eons and you'll never see them so long as there is a dominant present to supress them. Remove the dominant, and they manifest.

Muggles have no dominant which would supress magical traits. Which explains why, in canon, wizard/Muggle pairings invariably seem to produce wizards. Following this hypothesis, Wizard/Squib pairings are as likely to produce Squibs as wizards. Squib/Muggle pairings may produce wizards *or* Squibs, but never produce plain Muggles. Any Squib offspring are erroneously classified as Muggles. They are, in fact, undocumented Squibs.

Ergo: all "Muggle-born" wizards have at least one Squib parent. Some may have two, although the chances of producing a magical child in such cases drops to 25%, rather than the 50% typical to Squib/Muggle pairings.

Indeed, at a statistical probability of 50%, you would expect for the chances of a magical child to crop up before memory of a grandparent or great-grandparent having come from "somewhere else" to be higher than the indications in canon. But then since the original Squib ancestor probably spent a great deal of effort in concealing his origins, perhaps it's not that remarkable.

[mary-j-59.livejournal.com]

Oh, I love your gene theory! That the Squib gene would be dominant makes sense of the population figures that make no sense at all, otherwise. And I think it's likely the Creevey boys were indeed Halfbloods. But, as Oryx says below, they would have to be able to prove it to be allowed in the school as students. At the moment, my favorite theory is Terri_Testing's fictional one: that a lot of the Muggleborn kids were hiding out in the forbidden forest and that some of them had contacts at the school. Not canon, of course, but it makes some sense of questions like this. ;).

[jodel-from-aol.livejournal.com]

Well, we know that Colin could have come back due to the DA coin that he still had.

I suppose it's possible that Dennis just tagged along, but Minerva forced him to leave because he was underage. Colin may well have been 17 by May, so she couldn't chase him off as well.

But them being found to be halfbloods at some point off-page during Books 3-6, makes as much sense and doesn't require nearly as much back-bending.

[danajsparks.livejournal.com]

Actually, we're told in DH34 that Colin was still under-age.

Then Neville nearly walked into him. He was one half of a pair that was carrying a body in from the grounds. Harry glanced down, and felt another dull blow to his stomach: Colin Creevey, though under-age, must have sneaked back just as Malfoy, Crabbe and Goyle had done. He was tiny in death.

[jodel-from-aol.livejournal.com]

Ah. Okay. He wasn't underage by much. He would have been a 6th year, and due to turn 17 by the end of August.

So, then it probably was Colin that Minerva was trying to shoo away.

[oryx_leucoryx]

The battle took place in early May (May 2nd in interview), 8 months after the cut-off date for a cohort. So assuming births are spread evenly through the year, I expect one out of three 6th years to have been underage at the time of the battle.

[danajsparks.livejournal.com]

Ugh, I have spent way too much time trying to figure out wizarding genetics. Have you considered epigenetics as the source of the squib factor, something that causes a magical gene to be switched off and then switched back on several generations later?

[jodel-from-aol.livejournal.com]

Well, like I say, switching off a single magical gene wouldn't be enough to produce a Squib, because nothing we've seen in canon supports the claim that magic is produced by any single gene. So Squibs are probably not due to any gene being switched off, but by some other factor that interferes with *all* of their magical genes in some manner.

I'm not a geneticist, but that sounds more like something added than something faulty which later corrects. Because the magical traits are still there or there would be no Muggle-born wizards.

[danajsparks.livejournal.com]

OK, I think I see what you're saying.

But, once you allow for magical ability to be dependent upon more than one gene, I don't think you even need something like spontaneous mutation to explain wizarding genetic patterns.

Let's suppose that magical ability is dependent upon two genes, each with two alleles.

Gene 1 Alleles: U,u U is dominant for magical ability

Gene 2 Alleles: W,w W is dominant for magical ability

There are 16 possible combinations from these two genes. Both U and W are required for magical ability, so a wizard or witch could have the genotypes UUWW, UUWw, UuWW, or UuWw. And a squib or muggle could have the genotypes UUww, Uuww, uuWW, uuWw, and uuww.

So, even though U and W are both dominant for magic, it's still possible for two magical parents to produce a non-magical child and for two non-magical parents to produce a magical child.

If the magical population were to be very diligent about "breeding out" the recessive u and w alleles (by not reproducing with squibs), then, within 9 generations or so, a pureblood witch would have a 98% chance of producing a magical child with a pureblood wizard, a 90% chance of producing a magical child with a Muggle-born wizard, and an 81% chance of producing a magical child with a Muggle.

You can view the math for this here (https://docs.google.com/spreadsheet/pub?key=0Asq6Ul6gdxBCdHVhSlZidVVjV080TEtJWTdxa2VLZ2c&gid=0) (Like I said, I've spent way too much time thinking about this)

[jodel-from-aol.livejournal.com]

You probably know more about it than I do, but yes, making the issue dependent upon two factors rather than one would explain a lot of the variables. Unless the variables are single-gene additions having little to do with magical ability, but only operative in the presence of active conduction of magical energies.

[danajsparks.livejournal.com]

Lol, no, I make no claims of expertise when it comes to this stuff. I've been working on the math on and off for months, and I'm not sure if it's even right. I just don't have a life. :p

[oryx_leucoryx]

So 'true' Muggleborns are descendants of squibs on both sides, one parent Uuww and the other uuWw. And Hermione really is related to Hector Dagworth-Granger.

But besides the two main genes there must be minor modifier loci - that in themselves can't cause one to be magical, but if one is magical some alleles of these loci cause one's magic to be exceptionally strong. That would explain Albus, Tom and Lily (and probably Severus and maybe Harry too).

[danajsparks.livejournal.com]

----So 'true' Muggleborns are descendants of squibs on both sides, one parent Uuww and the other uuWw.

Well, yes, a Muggleborn's parents are both geneticallly "squibs," but their most recent wizarding ancestors could be many, many generations back.

And I think the truth may be that everyone has at least one magical ancestor somewhere in their family tree, in much the same way that probably anyone with European ancestry is descended from British royalty (http://www.theatlantic.com/magazine/archive/2002/05/the-royal-we/2497/). But that doesn't mean that everyone is carrying around magical DNA. For instance, if a first generation squib with genotype Uuww marries a muggle with uuww, then 50% of her children will be uuww- completely "muggle."

----But besides the two main genes there must be minor modifier loci - that in themselves can't cause one to be magical, but if one is magical some alleles of these loci cause one's magic to be exceptionally strong. That would explain Albus, Tom and Lily (and probably Severus and maybe Harry too).

Actually, I think the magical strength of Albus, Tom, Lily, Severus, and Harry may have something to do with the fact that they all have recent muggle ancestors. They all have a high probability of having the genotype UuWw, especially Tom, Lily, and Severus. This suggests to me that the "recessive" alleles u and w may, in fact, carry rather valuable genetic material that has been lost over time in the pureblood population. They may be alleles that affect factors such as intelligence, metabolism, mental stability, immune system strength, etc. So I suspect that Muggle-borns and Half-bloods tend to be more powerful because of hybrid vigor.

But I agree that there are probably additional genes that play a role in magical strength and specific magical abilities. Again, they may not be genes that only affect magic. For instance, there's a genetic disorder known as Ehlers–Danlos syndrome (http://en.wikipedia.org/wiki/Ehlers%E2%80%93Danlos_syndrome) that affects collagen and causes various connective tissues to be more "elastic." So maybe a metamorphmagus is a witch with something like EDS.