This thread is a spin-off from the 'Voldemort: Two interpretations' thread and is dedicated to the question of:

Whether the distribution of the ability to use magic among the population is based on genetics, or is it governed by the Potterversal Law of the Unexplainable, that clearly states: 'It's magic!'​

According to Taure, JKR said it was a gene. However, basic Mendel's laws make 'a gene' that governs magic impossible.

State your opinions, people. And back them up with something!

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And here goes my reply to e1.

 

A blind poll would help. Kudos for taking me up on the offer, Kerfidt.

So I decided to go back to the aforementioned thread and dig up what everyone had to say regarding this issue.

Fair warning, MASSIVE wall of text ahead.

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rocket runner

it makes sense that the more muggles marry into pure-blooded lines, the more diluted the magic in the blood gets which threatens magic's chance of survival. I know it never actually said this in the book, but genetics-wise it makes perfect sense.

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Tinn Tam

I have to object to that. A gene can be transferred from parent to child without ever being "diluted", no matter how many times the transfer occurs. It's not like blood. You may get "mixtures" of genes, but some genes stay intact through many generations -- and it's easy to imagine that the "magical gene", if there is such a thing, has properties of its own that prevent 'crossing-overs' that would denature it, and that automatically favour its expression (something like what's known as 'parental imprint').

So scientifically, no, it doesn't automatically make sense that the magic gets "diluted" as more Muggles marry wizards. Canon suggests that the "levels" of magical abilities greatly vary from one person to another without regard for their origins. Think Neville Longbottom versus Hermione Granger. Or, for the Hermione-haters/Lily-lovers out there, Neville versus Lily Evans.

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Sageun

I may be confusing some things but, as far as I understand it, assuming the "magic gene" is dominant, then the chances of a magical child being born would be slightly lower (ie. 25% lower). However, there is also the issue with squibs, which complicates the whole thing.

I agree with this. If I remember correctly, Dumbledore says something about how not having magic to rely on has made muggles more inventive and resourceful than wizards.

But wouldn't this also apply to Muggleborns, since it isn't they're fault that they had muggle parents? So, if they, like half-bloods, killed their muggle relatives, wouldn't that "redeem" them as well?

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rocket runner -- response to Tinn

If you follow the ideas of genetics, there are two ways for magic to pass on: blood or genes.

I don't think magic is a gene. There's too many contradictions. For muggleborns to appear, magic would have to be recessive. Following that theory, two carriers of the gene (but who are still muggles), would have a 25% chance of having a magical child. However, for a pureblood and a muggle to have magical children (i.e. Tonks), magic would have to be dominant. It just doesn't work.

The idea of magic being passed through blood makes a lot more sense. It explains why magical parents have magical children - squibs having magic, but not being able to use it. I'm pretty sure there are theories that magic lies dormant in squibs, and muggle-borns are the result of the magic "awakening".

Perhaps magic is like parseltongue - you either have it or you don't. Squibs almost contradict this theory, but maybe there is something that keeps them from using their magic, but still allowing them to pass it...?

Levels of magic might vary from person to person based off of environment, usage, emotion, etc. Voldemort used his magic constantly from a young age allowing him to being fluent with it. I think there's a difference in being able to perform more spells (Hermione) with having more power (Harry). One could argue that Neville never rose to his full potential because of the conditions he grew up in; so much pressure and disappointment from his grandmother decreased both his potential in magic and confidence.

Anyway, they're all just theories. I'm interested to see what you guys think - especially, when it comes to levels of magic.

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Sageun

@rocket_runner: I believe that magic works the same way muscles do. Some people have more potential than others but without exercise and training that potential is useless. For example, I don't think Hermione has more potential for power than Harry but, assuming she and Harry are on the same level physically (ex. speed, dodging) and mentally (ex. quick reactions), in a duel I think Hermione would win. Also, I think the reason Hermione can learn new spells much more quickly than Harry is because she has already learned so many more new spells and therefore has exercised her "magic muscle" more than he has.

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Taure

JKR has said magic is a gene.

Take it or leave it as you will. If you accept it, then there isn't much equivocation about it. If you deny it, there isn't much point in discussing the right or wrong of the matter as there's no longer any right or wrong to be discussed.

JKR has said this on her website: about magic being like an on/off switch, rather than a graduated thing.

Incidentally, a fun (but clearly not compatible with canon) idea, inspired by blood being brought up, would be magic being passed on from mother to baby via the placenta. Something in her blood which isn't filtered out and goes into the baby.

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Tinn Tam @ Sageun

Oh no, please don't do that.

Okay, fine.

EDIT: let this be my answer to rocket runner as well. It works too. But I only read his post afterwards.

There is more to genetics than Mendel's laws. First, a dominant gene may not be expressed fully -- this is called "penetrance". As an example, Huntington's disease is autosomic (i.e., not linked to the sexual chromosomes) and dominant with a penetrance of nearly 100% at 75 years old, but only 50% at 50 years old.

Secondly, there are sequences of DNA, most often situated before the genes themselves, that regulate their expression. They either enhance or repress it. Genomic imprinting (what I wrongly called "parental imprint" as an awkward literal translation from French) is a most curious way of regulating gene expression: according to whether the gene has been given by your mother or your father, it will be repressed or enhanced. This has nothing to do with sexual chromosomes, the genes are autosomic ones.

So even if it's a dominant transfer, the gene, if it's given by the "wrong" parent, won't be expressed.

Thirdly, we have the example of the X chromosome. Do you know why most females with a mutated X chromosome are only carriers of the disease, and not sick themselves? It's because they have two X's -- one healthy and one bearing the mutation. The two X's don't work simultaneously: one of the two is automatically inactivated.

Most females are healthy because their abnormal X is neutralised. Why does every cell systematically neutralise the 'bad' X? They could just as easily inactivate the healthy one. However, there is a preference for the normal 'X'.


So my hypothesis is: why wouldn't there be a preference for the 'magical gene' over the 'Muggle gene'? And if the Muggle one is inactivated, then magic would not be diluted. The same magical gene would be expressed as it's transferred, again and again.


Once upon a time, I had used these laws of genetics to give a (mostly) coherent explanation for the proportions of wizards, Muggles and Squibs. I forgot most of my reasoning -- my lessons of genetics were fresher in my mind than they are now -- but considering how many variables there are, JKR's views aren't so absurd. Of course, she probably invented her world while joyously ignoring the laws of genetics.

A possible explanation to this is 1. in DH 2. in my two previous posts.

In DH, Muggleborns are said to have stolen their magical powers. In pure-blood minds, magic must be inherited; so, pure-blood wizard? Awesome. Half-blood wizard? Alright (understand: they took everything from their magical parent and the other just gave 'normal' genes -- like those for the eyes, skin, hair, etc.). Everything in between? Fine.

But Muggleborn? Who the hell are they, these Muggles who suddenly find themselves with magical powers? Where did they find them?

It is conceivable that pure-blood wizards can't stand the idea of two Muggle parents creating a wizard. Muggles creating magic, in fact. They've either stolen it or are abominations of nature. And they will still be wizards who came out of nowhere even if they murder both their parents and their entire families.

Unlike half-bloods, who already have a spot in magical history.

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rocket runner

@Sageun : I agree. It's like muscle memory: the more you do something, the easier it gets.

@Taure : I wasn't ever denying that magic was a gene; I was explaining that magic being passed through blood made more sense to me. However, I wasn't aware of JKR's comment regarding magic. Thanks for telling me.

@Tinn Tam : I admit, I was just going off of my knowledge of Mendel's laws when arguing my disbelief of magic being a gene. I'm afraid I'm woefully ignorant when it comes to genetics outside of that. My apologies.

If you ever found/remembered your explanation, I'd love to read it. It's quite interesting.

I'm sure JKR's reasoning behind everything she can't explain goes something like, "Why couldn't this work? It's magic!" And of course, she can get away with that.

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e1 @ Tinn

LOL @ sexual chromosomes.

/nerd rage

As for the rest, this isn't a lesson in Biology. Half of what you mentioned does nothing to justify your hypothesis.

Genetic imprinting -- the chances of that happening in mammals are less than 1%. And you're also assuming it's target-specific. A 'magic' gene, even if it existed, would not be imprinted every time - simple mathematical probability would see to that. A rare phenomenom such as this cannot be used to justify the existence of the entire magical population.

Sex-linked phenotypical expression -- why even mention it? Magic is NOT a sex-linked trait. If it was, then you'd have more wizards than witches (which is clearly not the case in canon).

Clearly, you haven't given this much thought. Or maybe, it's just a case of miscommunication. Either way, we are not in the same boat. All you did was slap together a few genetic phenomena and derive a hypthesis out of nowhere.

Kinda like something I would do in a maths exam when I'm having trouble proving LHS = RHS. Put random BS in the middle -- add a generic conclusion stating "therefore LHS = RHS", and hope for the best.

TL;DR

THIS.

A trait can be dominant, recessive, co-dominant or sex-linked. Since you can be either magical or non-magical, but not both, we can safely rule out co-dominance or incomplete dominance. Sex-linked is out as well (read above). Hence, we can conclude that magic is either dominant OR recessive. From rocker runner's post, the existence of a 'magic' gene poses a contradiction - ergo, scientifically impossible.

If classical biology says it ain't, then it ain't.

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Taure @ e1

And everything in the HP world follows the rules of science, amirite?

The following seems to be a perfectly feasible in-universe explanation: the magic gene follows alternative rules of genetics which would take account of magical factors of which traditional genetics is unaware and unaffected by.

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Kerfidt

Personally I support the genetic point of view. However, when trying to explain the accessibility of magic to people, it seems to me that the Occam's Razor isn't working. Clearly one 'magic/muggle' gene can not regulate the distribution of 'The Gift of Magic' as we see it in the Potterverse.

Therefore, let's go advanced.

Consider, for example, that a 'magic gene' is in fact a series of genes, not very long to avoid magic's elimination due to statistical reasons, but not very short for it to be impossible to link the magical attributes to certain phenotypical traits. Even if the genes themselves are binary switches, the whole system has a lot of possible states, one -or more- of which enable access to magic. And, of course, the series doesn't have to be continuous. One gene here, a couple there, interspersed among countless others... As we don't know the true nature of the so-called 'magical core' of a wisard, we can't rule out the possibility of several generic genes creating a magical combination. Placed in the right loci, they can gain the trait of heredity, all the while allowing for squibs to be born.

And, while we are at that, multiple untraceable genes may subtly control the finer aspects of how a person uses magic. As there are (at least, 'must be', since I do not remember for sure) some... conditions to which people are predisposed due to their genome, and by conditions I do not necessarily mean illnesses, it is also definitely not out of the realm of possibility that the predisposition to a certain field of magic, e.g. Transfiguration of Charms, -which is, by the way, also affecting the wand most compatible with a wisard, which in turn has to be touched when checking for compatibility (sampling the DNA?)- is also regulated by the 'magic' genes.

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e1

And everything in the HP world follows the rules of science, amirite?

Meh. Frenched up version of saying "Hey, it's magic". Care to elaborate on these 'alternative rules' and 'magical factors'?

Lol. Classifying magic as a multiple-gene inherited trait sounds even more ludicrous. What are the odds of the genes lining up to provide the 'right' combination every time? And this is without even considering any instances of random segregation or crossing overs that might take place during meiotic division.

It's not your reasoning that's flawed. You're simply backing the wrong horse, mate. Your predilection for the 'magic gene' theory is prompting you to inject whatever genetic-related knowledge you possess into your arguments, no matter how ridiculous they sound.

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Chime??

I think Magic is just like SW's "Force" you have people who are born 'force sensitive', they have a degree of control of the force depending upon how much flows through them.

What governs that is usually fate, like in Harry's case, who is gifted with above average magical prowess because of his 'destiny'. It isn't genetic, whatever Rowling claims, it's simply a matter that is governed by universal laws not acknowledged.

I mean it's not the first time an author totally ruined their own story logic (lol in bf midichlorians) with some half-assed explanation.

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Taure @ e1

Er, no, actually. I find "it's magic" a completely satisfactory explanation as to why it breaks the rules of genetics, as, you know, it's magic.

But such rules, whatever they are, would have to enable it such that both Muggleborns and squibs could exist, and squibs be much rarer than Muggleborns.

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rocket runner @ Taure

Even magic follows a set of guidelines - you can't create food or bring people back to life, for example. However, if we take JKR's word for it that magic is a gene, and we pretty much have to, then there has to be a different set of genetic rules that magic follows. Obviously, our genetics doesn't explain the existance of squibs, muggleborns, and the rest.

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Kerfidt @ e1

Okay. I'm set in my ways and am not willing to part with them without fight. I'm also thoroughly uneducated in genetics, my knowledge of the subject limited by the basic school course. (But that course was a good one. I think.) I, however, am wondering as to the exact extent of your understanding of the subject. My reasoning for the doubt is this: first of all, as far as I understand it, 'instances of random segregation' happen in EVERY meiotic division, being the act of separating alleles that go to different gametes, and 'not even considering' them is... strange. Secondly, the crossing overs, while theoretically being able to screw everything when we are talking about multiple genes, are known to leave certain pieces of chromosome intact in almost all cases. I do not remember the exact term, but there are places which seem to be 'protected' from such meddling. That is exactly what I was referring to when speaking about the genes being placed 'in the right loci'. I admit, it sounded unclear.

On the other hand, your earlier reply to Tinn Tam had an effect of convincing the audience that you know what you're talking about. Maybe the way I read your words to me is another instance of miscommunication. So please tell us, what is the extent of your involvement in genetic research? Because if, for example, you are a renowned geneticist, or at least are studying it in a university/college, I will publicly acknowledge your superiority in the subject and will humbly request a thorough explanation of why, exactly, you are claiming the chances of my severely underexplained and underdeveloped system to work to be critically low.

And I have a backup plan to support my theory in case you prove that, from the point of view of serious genetics, it sucks. It will involve a compromise between Taure's and rocket_runner's opinions, and I hope I won't have to resort to that, but...

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e1 @ Kertfitd

Ditto. I'm 18. Were you expecting a PhD? As to what I've said in my earlier posts, I admit I might have come off as a little arrogant. Nah scratch that ... very arrogant sounds about right. For that, you have my humblest apologies.

Rest assured, everything I have stated concerning genetics is indeed factual. You should atleast do me the courtesy of looking them up in google or a certified textbook before you start casting aspersions on said statements.

Again, you misunderstand me. I was merely noting how everyone arguing in favour of the 'magic' gene conveniently forgot to mention these issues; because as you yourself said, they have the potential to screw everything when we are talking about multiple genes.

Well Tinn did sort of bring this up, but then again, she presumed that the magic gene would not be affected by 'crossing overs' -> consequently making this a purely hypothetical assumption of no consequence.

The way I see it, you're basing your arguments on something you cannot fully recall. This is not acceptable. In any case, I felt obligated to look this up on google -- to no effect. Perhaps my google skills aren't up to par. Would you mind linking me to a reliable source?

However, I did come across an interesting tidbit that you might be alluding to ...

Hmm ... food for thought. Perhaps, the 'magic' gene would not be subjected to crossing overs if placed 'in the right loci'? But then again, that's still assuming a lot, since we are talking about a series of genes.

I --

Touché.

Agreed. Perhaps you should do the honours?

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:awesome There, I've done my part. Gawd! I have WAY too much time on my hands...

 

The poll lacks the option, "It's genetic, but not a form of genetics familiar to us". The phrasing of the poll options is rather weighted as well. Biased polls ftl.

 

Word.

That's all I have to say on the matter...

 

On the topic of "dilution of magic", JKR has said that the magic gene is extremely "resilient". Not a technical genetic term, but then that just backs up my conception (in an in universe way, in an out of universe way it's clear JKR just doesn't know what she's talking about) of an alternative genetics.

The magic gene somehow propagates itself in a way unknown to mundane genetics.

 

Hm. An easy explanation may be that, while the magic gene is in fact something extremely rare, it is the parents' magic that preserves the required gene/sequence. As we can see, in the Wizarding World it is desirable to have a magical offspring. The will/intent/something of the parents activates some mechanism that conserves the 'magic gene', whatever it is, and passes it to their child. In the Muggle world, the existence of magic is unknown, and even if the parent(s) is/are Muggleborn but did not have a prolonged exposure to Wizarding Culture (for example, if they were not accepted to a magic school, or if they declined the invitation), the magic preservation mechanism is not activated. In this case normal genetics and probability theory apply, and the magic gene hides or disappears. That's why we do not see families with long magical history emerge 'from nowhere'.

But, of course, if someone is able to come up with a good purely-muggle-genetic model of magic genes, it would be much more awesome

 

@Taure

I'll quote what Tinn had to say about JKR ...

Her word isn't worth shit in this thread. Canon compliant or not, the aim of this discussion is to find a 'purely-muggle-genetic model of magic genes' (as Kerfitd so eloquently put) -- that is if one exists. So if you've got nothing more to add than a few vague statements concerning 'alternative genetics' and how the so-called 'magic' gene propagates itself through mechanisms that remain, as of yet, elusive to contemporary genetics, then save yourself the effort.

I've said this before, and I'll say it again:

Have you, even for a second, considered that the answer may not lie in genetics? Given the number of essays concerning magical theories you've tackled, I'd say you have.

On that note, I concur with what you had to say regarding the phrasing of the pole. The second option (magic can't be explained), while being an appropriate alternative, turns a blind eye on any non-genetic related phenomena that might explain the origin of magical traits.

Now that I've tried my best to disabuse you of your rather pedantic notions, can we please move forward?

 

No it isn't. The purpose of this thread is to ask "how is magic inherited". You're trying to create a false dichotomy by saying the only two possible answers are "muggle genetics" or "non-genetic explanation".

This is simply not the case.

The reason why I'm not outlining explicitely any rules of the postulated "magical genetics" is because that any such rules I would come up with would be of my creation - fanon - not based on canon.

And in discussions like these, "fanon" is synonymous with "useless"

 

Yep, the phrasing of the poll is uh... lacking. To defend myself I'll say that a) I was in somewhat of a hurry to gather my stuff and catch a bus home, and b) these two were not even dominant, but the only two variants mentioned (and discussed) in the original thread. That is not a very good excuse though. I should have given more thought to the wording of the poll options.

Well, if someone has an alternative opinion, he is welcome to vote non-genetic and post an explanation of his/her theory here. I think such a contribution to the discussion will be appreciated by all of us.

Oh, and while we are at that, could you guys please post some links to plausible theories on the nature of magic? (Taure, as you've been accused of 'tackling a large number of essays blah blah', I'm looking primarily at you.) Is the concept of a 'magical core' even canon-compliant?

 

I'm no geneticist, but let me gather this:

1. 99% of genes remain constant throughout every living human alive today, 98% between us and monkies.

2. That 1% which differs is what determines characteristics of eye color, hair color, height, weight, personalty leanings, and other varied traits.

That said, we all have 2 arms and legs (unless by genetic defect we are not born with them), we all eat and drink, and our organs function in all the same way (I assume so anyway). Thus, if we assume magic is genetic (as Taure says, a false assumption, but let's assume it for now), magic can be one of two things:

A trait which can be inherited or carried during the formation of the zygote.

Something genetic which is "absolute", like an arm or a leg.

Perhaps magical people are like a man who is born with an extra eye, only, it is genetically reproducable (that man's children will have 3 eyes). It's "hardcoded", meaning, it is mostly certain to be passed on.

That is why squibs are rare: it is a case where the magic gene fails. It is like being born without a leg.

By this theory, humans are one species of human, magical humans are another.

I'm probably butchering the science of it, and I may be wrong there are "hardcoded" traits to humans (I don't think so actually, but it's all just an idea I'm tossing here), but does what I'm saying have a shred of logic to it? If a magical person has a child with a muggle, magic is gaurenteed, unless the gene flubs and you get a squib.

Addendum: A magical person's skill with magic is likely unrelated to genetics. I do not agree with the idea that magic is simply a 'muscle' or a mystical repository which can shrink or enlarge.

 

It's probably genetic.

1) It's hereditary from what we can tell in the books.
2) Some of people who are born from magical parents aren't magical. Which rules out some deity giving it to some person(s) and their offspring.

Other than that, there's no real telling.

 

The three sides to this issue seem to be:

1) Magic has some function in relation to genetics, yet the very notion that it is magic means that it can not be attributed to modern, rational genetics such as basic Mendelian theory and must be attributed to alternate, magical genetics.

2) Magic follows the very same genetic theories used in modern sciences.

3) Magic has nothing to do with genetics at all.

Though I believe the argument that this is JKR is valid enough in and of itself, we have had way too many discussions about magical theory and wizard vs. muggle to pull that out here. So instead, I'll just try and say my theory.

Here's a first point. Chime said:

Of course magic is related to genetics. If it wasn't, you couldn't pass down specific and rare abilities through a family such as Parseltongue. If you want Canon, Taure has already given it to you, and that's what this discussion is on. Did we ask about your origins of magic. No, we want canon origins, and JKR said that it is a gene.

So let's flesh the reason why the second and third arguments are wrong, okay?

A. JKR said magic is a gene.

B. Modern Genetics says that a magical gene is impossible.

So if A doesn't equal B, we have a problem. What's the kink in the chain? Modern genetics. So what has to go? Modern genetics.

That means that, indeed, A does now equal B because guess who wins?

Option number 1.

 

Magic came from God...

On the 8 day, he woke with a hangover from 7th's night parting and let out a mighty belch. Slobber and all kinds of shit came spewing out of his mouth.

Adam and Eve, being the ignorant fucks that they were created as, decided to eat some of this shit. Cause you know, everything that comes out of God's mouth is the fucking truth.

God proceeded to bitch slap said ignorant fucks, cause his vomit is some holy shit. Might cause Adam or Eve to turn into smart ignorant zombies... or some shit like that...

Alas it was too late, Eve (being the traitorous bitch that she is) had already digested a squirt full. Thus, her offspring would forever be plagued with the curse known as magic... Might skip a generation or 5, but who is really counting?

I wont tell you what she had to do to produce the first werewolf *shudders*

tl:dr
Magic is genetic and I am drunk for the 4th...

 

Whoa, whoa, wait a minute! Who said that? At the moment when this thread was created, the whole point of the conversation was to come up with a genetic model that would satisfy the initial requirement of fitting into JKR's world, or to prove that it is impossible to do so. So far the only thing we've determined is that, if we adopt a constructive approach, a single gene would not provide us with the answer. Surely you don't mean to punch us in our collective nose with the article in the phrase 'Rowling said it's a gene'? Because if you do, it will be so utterly inappropriate in a scientific-like conversation we're having here...

Or, to put it another way, the fact that A doesn't equal B proves nothing when the actual problem is to compare A and an integral of B.

 

And Ron. And Dumbledore.

 

I've decided that Voldemort's name isn't Tom.

You think it is?

Well, that's CoS, and I've decided that because CoS is my least favourite book in the series I can disregard what it tells us.

(I can't believe some members are still having a hissy fit over DH not going the way they wanted it to).