Is magic genetic?

[Demetri]

I know many of you at the sight of this title say that JKR said it didnt have anything to do with DNA. But though I love JKR and think she is a brilliant writer I seriously have a logical problem with this.

I know it seems really arrogant for me to call her wrong in her own world but I am basing my claims entirely on logic.

First of all, if it is not genetic and has nothing to do with DNA then how come most of the time having two wizarding parents leads to a wizarding child. If magic is just something that happens spontaneously then why arent there more PURE muggle families (not ones with magic deep in it) with a random wizard in it?

Furthermore, how could pure blood families have been maintained without a random squib in the mix? This seems to make no sense to me.

And also, what about Hogsmeade? I'm sure people live there or else there wouldnt be so many shops open all year around. How can it still be the only pure magical town if being magical was a roll of the dice?

Also if it wasnt genetic then how could there be degrees of skill in magic? It seems odd how that if it just happened all people are just equal.

Now while I'm not saying they it is as simple as dominant or recessive genes but I do think it has a lot to do with DNA.

[harryfantotheend]

Wow...you know i'm not one to go against JK, but you've got some great points there. However, I would say that JK can do whatever she wants...and in this case it looks like there's no rhyme or reason. But very good points you brought up!

[Barbara Kennedy]

Here are the threads I found on genetics.


Muggle-borns genetically stronger than pure-bloods? (http://www.cosforums.com/showthread.php?t=24491)
Genetics of Red Hair ( http://www.cosforums.com/showthread.php?t=28345)

(About a year ago we had a thread on this question, but it seems to be gone now.)

[Demetri]

Yea..I would have posted it in the First one but this is a bit different than that. I only posted it differently because it was explicitly linking to an answer given by JKR about the genetics of magic not in comparison to muggles but in comparison to each other. Like how magic continues etc. Sorry though...

[Wab]

That magic almost always runs in families more or less confirms that it's in the genes.

[Barbara Kennedy]

Yea..I would have posted it in the First one but this is a bit different than that. I only posted it differently because it was explicitly linking to an answer given by JKR about the genetics of magic not in comparison to muggles but in comparison to each other. Like how magic continues etc. Sorry though...
No need to be sorry, I only put the threads up there for reference.
Yours is good.

[Ivan34]

I have to agree with you, I dont keep up with JKR's interviews a whole lot. So I always thought that magic was passed through dna or something like that. It just only makes sense.

But we dont know every person in her world, maybe there is a squib in the Malfoy family that we dont know about, that the Malfoy's dont want ANYONE to know about.

[Demetri]

That would be quite interesting. The poor boy would probably be locked in the mansion and is being transfigured into a House Elf as we speak!

Actually, knowing the Malfoys that wouldnt be too unlikely...

[Ivan34]

That would be quite interesting. The poor boy would probably be locked in the mansion and is being transfigured into a House Elf as we speak!

Actually, knowing the Malfoys that wouldnt be too unlikely...


No it wouldnt be too unlikely, but knowing the malfoys they would either turn their "non magic" child into a slave or kill them.

[Demetri]

Yea I really cant see this Draco becoming good argument. Well that isnt true, I can see it and it would be a nice (though trite) turning point. But I think the Malfoys are what Hitler would have loved to be (elitist AND arian).

I think that actually we could be on to something. All of those who are proponents of the Draco turning good theory (I actually love the Draco chickens out theory) I think this could be the way. Imagine the arrogant Draco humbled by having a squib brother or sister or family member. And better yet he didnt even know about this person. That would be a great way of breaking him. And then he would really want to show his allegiance to the cause for Voldemort but in the end he chickens out.

Interesting...

[Ivan34]

yes but then you have famlies with 7 kids and all are magical. oh well maybe we will find out some time what really makes a wizzard a wizzard.

[Demetri]

Hopefully or else I will be a bit disappointed in JKR. This is one of the only major flaws in the world she made. But even so I have to hand it to her having only this one logical flaw (though it is a rather large one) in a world she herself made up is impressive. And I am not talking about little errors like the wand or the prefect point system. I mean in the basic ideas of the world that she normally describes in such symbolism (I vividly remember one critic saying that Rowling describes things so wonderfully she herself could be a graduate of Hogwarts, which is quite true) that it is spell binding.

I do hope she fixes this though. I am just not really sure how she could. I cant think of an answer to it really, but she probably knows something I dont.

[Creatively Evil]

You have an interesting point there Demetri, one of the errors JKR may not have overlooked. But, it's her books, and she can do whatever she wants with them!

[Demetri]

So true. Hurrah for mass media and gigantic publications!

[Deliah]

About Hosmeade - there are not that many witches and wizzards and this is probably the reason why there is only one magical town in Britain. But I have always wondered why wizzards rather live somewhere else, close to a muggle town or even in a muggle town. It would be much easier to live in Hogsmeade, where there wouldn't be the need to hide what they are ...

The reason why there are not that many wizzards in muggle families is easy to explain - if you look at different mutations in human genetics, there are some that happen quite often but there are some that are very rare. (for example compare the number of kids that are born with 3 21th genetics to the number of kids being born with 3 gender genetics)

[Demetri]

Yea but then it is based on the genetics and your lineage. I am simply pointing out that JKR said it wasnt at all based on DNA and logically I dont think that is very sound.

And about Hogsmeade: I dont necessarily think every person there has travelled there. Surely there must be families. Having an entire population (which is rather large apparently) built on immigrants seems a bit odd.

[MalfoyIsMINE]

hm, thinking about this with no logic at all, maybe its just something inside of someone muggleborns heart that allows them to become a wizard....i dunno...but very good point!

[Deliah]

And about Hogsmeade: I dont necessarily think every person there has travelled there. Surely there must be families. Having an entire population (which is rather large apparently) built on immigrants seems a bit odd.

Yeah, sure Hogsmeade has a "native" population, but what I mean is - imagine you would be very different from the other people in the town you live and you would be forced to always hide that fact - wouldn't you want to move to a place where all the people are like you?
And take for example families like the Malfoys - they look down at muggles. Why do they not live in a magical neighbourhood with no muggles near?

[Demetri]

I see your point but I dont think Malfoy was a good example because if he was in Hogsmeade all the shady dealings he does would be far closer to Dumbledore and I doubt he would like that.

But I guess I see what you are saying, but it could be for various reasons including availability etc.

But I digress from my initial point that being a native of Hogsmeade can't necessarily make you different.

For example, as MalfoyisMine said about having something inside you, how would that be different if you lived in Hogsmeade. So if some of those people lived in muggle towns would they have been muggles or what?

I think it has to be genetic.

[grawp66]

I think that JKR meant that genetics don't play a part in how powerful or adept at magic a wizard is, and not that genetics don't play a part in whether a child will be born magical at all. I don't think she was saying wizards are born totally at random. She was saying that it doesn't matter how powerful someone's ancester's were - each witch or wizard's power comes from themselve's, not genes. This would explain people like Neville. His father was a powerful Auror, but he didn't seem to have inherited much of that power. There's also Hermione - a great witch whose parents are muggles.

If wizards were born totally at random, it would be extemely hard to keep the wizarding world secret, becasue magical people would be poppong up everywhere. Surely the worlds would merge.

[dobby_rocks]

Though you do have some good points. It is JK world and she can have it be however she wants it to be. If she says that Magic is not determined by DNA/Genetics. Then I think its that simple, this isn’t the real world there doesn’t have to be an exact answer to everything, heck even in the Real world that could be said. Some things are just the way they are and cant be explained. I like it better that Magic doesn’t come from Gene / Dna I think it makes it more interesting . That you don’t have to have it in your family to be able to get magical powers and stuff. Maybe it is something in people but it has nothing to do with genetics but something deeper then that. I also think it would be cool to be muggle born and be able to say i am the first witch or wizard in my family

[Fingolfin]

Magic doesnt have to be passed on through genes i think maybe the magic that is in the parents flows into the child ... it doesnt have to be in the dna ... magic isnt a science, i was just looking at the thread on red hair aswell and um ... JK is a writer not a scientist , im positive that she wouldnt be checking weather the books are scientificaly correct they blatantly arent !

[Demetri]

If it is passed through the parent then it is genetic.

I recognize it is JK's world but that doesnt mean she can throw logic out the window.

[Shauna]

First of all, if it is not genetic and has nothing to do with DNA then how come most of the time having two wizarding parents leads to a wizarding child. If magic is just something that happens spontaneously then why arent there more PURE muggle families (not ones with magic deep in it) with a random wizard in it?

Perhaps it isn't dominant genetically (which is how I have always thought of it), but the wizarding power seems to override the being a Muggle power...if that makes sense. Having a wizard child in a Muggle family is just a random occurrence. Instead of thinking DNA, just think a random variable.

Furthermore, how could pure blood families have been maintained without a random squib in the mix? This seems to make no sense to me.

And pure blood families could just as easily have a Squib, I think. It is just a random occurrence, like a genetic mutation.

And also, what about Hogsmeade? I'm sure people live there or else there wouldnt be so many shops open all year around

I'm sure there are a couple of Squibs living in Hogsmeade. Look at my next answer:

How can it still be the only pure magical town if being magical was a roll of the dice?

Being magical isn't a roll of the dice. Have you ever taken Statistics? It is a non-random variable. I'm going to give some examples with numbers (these are just numbers I made up, doing all the calculations would take me forever):

Perhaps two pure blood wizards have a 99.9% chance of having a wizard child, and a .1% chance of having a Squib. But a pure blood wizard and a Muggle wouldn't have a 49% chance of having a wizard child (98/2), because being a wizard is much, much more "dominant" over not. So they might have something like a 98% chance and a 2% chance, respectively. I could go on, but do you see the general idea?

Also if it wasnt genetic then how could there be degrees of skill in magic? It seems odd how that if it just happened all people are just equal.

As far as skill level goes...it's magic. We don't have to understand exactly what makes one person better at magic than another.

Shauna

[Demetri]

Perhaps it isn't dominant genetically (which is how I have always thought of it), but the wizarding power seems to override the being a Muggle power...if that makes sense. Having a wizard child in a Muggle family is just a random occurrence. Instead of thinking DNA, just think a random variable.



And pure blood families could just as easily have a Squib, I think. It is just a random occurrence, like a genetic mutation.



I'm sure there are a couple of Squibs living in Hogsmeade. Look at my next answer:



Being magical isn't a roll of the dice. Have you ever taken Statistics? It is a non-random variable. I'm going to give some examples with numbers (these are just numbers I made up, doing all the calculations would take me forever):

Perhaps two pure blood wizards have a 99.9% chance of having a wizard child, and a .1% chance of having a Squib. But a pure blood wizard and a Muggle wouldn't have a 49% chance of having a wizard child (98/2), because being a wizard is much, much more "dominant" over not. So they might have something like a 98% chance and a 2% chance, respectively. I could go on, but do you see the general idea?



As far as skill level goes...it's magic. We don't have to understand exactly what makes one person better at magic than another.

Shauna

-About the random variable bit if that is true how odd is it that out of all randomness all of the weasley's were magical, and that pure blooded families have existed for so much. Now if the magical variable is increased based on who your parents on then that is basically the definition of genetics (kinda..)

- If beinga squib is a genetic mutation then that concedes that genetics has a major place in the magical process

- I have taken statistics and I understand that but remember as the bolds (mine) prove you said it was random first then non random. If it is non random then the statistical probability of being a squib is dependent upon your parents make up and is therefore genetics

-It basically sounds like you are agreeing with me because as long as you are adjusting the statistics to take into consideration the family and if they are magical then I have proven it is genetic

-And just because this is JKR's world doesnt mean she can claim anything and make it magical. If Sirius just popped back in Grimmauld place you would want an explanation? Similarly I think this needs explaining to provide for the full, rich world she has put before us.

[Kirsten]

I think if magic and all of the books were true then we would have a strong argument that magical ability is a genetic trait, probably recessive. But given that the books are JKR's fictional creation, I think we can assume that she is saying she has not considered the genetical implications of magical ability, it's not relevant to the stories, and why worry about it? It's just fanwank - fun, but ultimately meaningless.

[Demetri]

It couldnt be either dominant nor recessive given the fact that two wizards could have a squib.

I.E. D=muggle r=wizard

mother: rr
Father: rr
Child: only possibility could be rr

I think it is likely a chromosome that has evolved that stands on its own.

[Kirsten]

An extra chromosome? Magical ability is down to genetic freakdom?

[squirpy]

There actually was a thread about this here: http://www.cosforums.com/showthread.php?t=21588

I'm going to repeat my post from there, because this seems to be heading in a more genetic direction.

ok, if M is muggle and it's dominant, and w is wizard and it's recessive, the gene chart thing would look like this (I hope this formats right):

-------------------
......M | w
-------------------
M | MM | Mw
-------------------
w | Mw | ww
-------------------

so if two Muggle parents with one wizarding gene have a 1/4 chance of having a magical child, and a 1/2 chance of having children with one hidden wizarding gene.

But if a pure Muggle (MM) mates with a wizard (ww) or a muggle with the gene (Mw), they have no chance of having magical children. So unless a wizard mates with an Mw muggle or a wizard, all their children will be squibs.

This leads me to beleive that there is no scientific basis for magical genes in Harry Potter (unless it's one of those if you have this gene and this gene, the magic gene turns on things).

[Demetri]

I know but I am saying that it couldnt possibly not be genetic but also it couldnt be genetic as in recessive and dominants because that would be illogical. Look to above posts.

[squirpy]

You just said the same thing twice.

I know it's illogical, but genetics doesn't really work here. Unless the magic gene is hanging out on the end where it can easily be mutated.

It could also be that thing that Labradors have: http://www.labbies.com/genetics.htm

[Demetri]

Genetics is the only thing that works here. What I meant though was that logical genetics (dominants and recessives) dont make sense but how could it not be genetics with my abuse logical points.

What I think it is is an extra chromosome or something or else it simply wouldnt work.

Unless you could tell me why all of the Weasley's are magical. How pure blood families continued being magical, how Hogsmeade is able to renew its pure magical population, and why most wizard parents have wizarding children I'm afraid logic says it is genetics.

[squirpy]

look at the link... pretend that the blacks are muggles and the yellows are wizards.


the Weasley's aren't all magical. They're mostly magical - there's a second cousin who isn't magical, so it does happen.

[Demetri]

I know but if youy are saying it is a roll of the dice how odd that only one of them (likely related to a muggle somewhere along the line) rolled the Muggle side (you get the idea).

It has to be related to genetics, I really cant see another option...

[squirpy]

I'm not saying it's roll of the dice. Did you look at this (http://www.labbies.com/genetics.htm)? That's not roll of the dice, that's about epistatic genes. It's a bit like a double layer of dominant/recessive. Black would be muggle, yellow would be wizard, and I'm not exactly sure what chocolate would be.

[SiriusLives1621]

Maybe there's something deeper than DNA when it comes to magic...I've never realy thought about it and I have to leave for now, but I will ponder it and get back to you when I've thought of something good...

[squirpy]

Hm. ok, now that I'm looking closer, I'd have to say that chocolate would also be magical (maybe people who are a bit less magical?), because otherwise you can't get squibs. If you consider chocolate and yellow to be magical, then the system works well.

[TaraBrady]

Maybe magic is sort of something that you can 'catch' from your parents; being in a magic saturated environment in utero makes you more likely (if fact, almost certain) to have magical ability. But even in the most intensely normal households, there's some magic floating around, which would explain occasional magical births to muggle families.

I know there are holes here, but Jo says it's not genetics, so I'm going with it. I can only think of two squibs offhand, but there seem to be a lot of muggle born and half blood students at Hogwarts, so either I'm missing something or the wizarding population is skyrocketing! Otherwise, Squibs and Muggleborns would be about even.

Has anyone ever gone through and tallied up how many pureblood, halfblood, and muggle-born people we've met in the series? It might be interesting to see what the actual ratio is between magical children born to muggle parents and those born to wizard parents. Maybe we rarely hear about Squibs because families don't talk about them, like Ron's cousin the accountant. (Oh! That makes three Squibs!) Or maybe all those muggle births are to compensate for all the deaths that occurred during the last war.

[squirpy]

I would guess that even if there are a lot more squibs, we don't see them much in the books because the books are more centered around magical people.

[Shauna]

-About the random variable bit if that is true how odd is it that out of all randomness all of the weasley's were magical, and that pure blooded families have existed for so much. Now if the magical variable is increased based on who your parents on then that is basically the definition of genetics (kinda..)

Well, right. It's based on the workings of genetics, because JKR made it up. But it doesn't have anything directly to do with DNA.

If beinga squib is a genetic mutation then that concedes that genetics has a major place in the magical process

Go back and read my post. I said it was random like a genetic mutation, being as both things are random. I never said it was a genetic mutation.

I have taken statistics and I understand that but remember as the bolds (mine) prove you said it was random first then non random.

That is not what I meant. Perhaps I did not explain myself clearly. When I said "random variable" at the beginning, I meant a variable having nothing to do with DNA. That was a poor choice of words; I should have said "separate variable."

If it is non random then the statistical probability of being a squib is dependent upon your parents make up and is therefore genetics

No, it's not. JKR has said that magic has nothing to do with genetics. Therefore, whether a person is magical or not is it's own separate variable. It can still be within you and it doesn't have to be genetics. That's what makes it magic.

It basically sounds like you are agreeing with me because as long as you are adjusting the statistics to take into consideration the family and if they are magical then I have proven it is genetic

I'm not agreeing with you or disagreeing with you; I'm simply trying to give you explanations to your questions that go along with what JKR has said.

And just because this is JKR's world doesnt mean she can claim anything and make it magical. If Sirius just popped back in Grimmauld place you would want an explanation? Similarly I think this needs explaining to provide for the full, rich world she has put before us.

It's magic, man. It is not always logical. I tried to make a bit of sense of it for you, because it seemed like you were asking questions and wanting answers. Do you want your questions answered or do you want to prove a point that magic is genetic? Because I can tell you right now, if that is what you are trying to do, there is no point in arguing anymore. JKR said it isn't genetic.

That should be enough for all of us. You're going to have to reconcile what she said with what is possible, and that is all I'm trying to do.

Shauna

[emerald eyes]

I think its just magic. It just happens. Accept it. Some things don't need to have a logical explanation. If Jk says its not genetics, why even the debate? To say that its genetics I think takes away the "magic."

[Demetri]

The thing that is taking away from the magic is its illogical nature. And remember if you think magic must have something to do with genetics you are on my side no need to argue.

[Teen Angst]

i wouldve thought magic did had something to do with genetics. it would explain alot. how muggle parents got a witch or wizard child because in their family couldve been a long line of carriers. but then again that would dissprove about the "not a magical drop of blood" in their body thing.

[Bouncing_Ferret]

I think its just magic. It just happens. Accept it. Some things don't need to have a logical explanation. If Jk says its not genetics, why even the debate? To say that its genetics I think takes away the "magic."

Precisely! :D In the books, muggles are always wanting logical explanations for everything, aren't they, because they can't accept something that doesn't conform to their own experiences or beliefs, which is exactly what some people seem to be doing in this discussion. It's magic, it doesn't have to make perfect sense. And I for one am sticking by whatever JK says, regardless of how sensible it is, because it's her world, and it certainly doesn't make it any less magical an experience for me, anyhow! :)

...But just one teensy little idea, that I'm ashamed of because I hate and am awful at science, but here goes - could magic be like a virus? You know how in some people they aren't effected by a virus, but when they pass it on to others, like their children, their children are effected? And wizards naturally keep on passing down the virus to their offspring, but ever so occassionally a child has a natural immunity - a Squib. Obviously it wouldn't be contagious to other people, otherwise there'd be adult wizards and so forth popping up all the time after rowdy office Christmas parties.

Don't get mad at me for that super bad theory, as I've no understanding of how a virus actually works, and I think it's a terrible, horrible thing to say anyhow, but it's still an idea, eh? :p

[Jessica]

Could a kind Mod please merge this thread with this one:


Muggle-borns genetically stronger than pure-bloods? (
http://67.19.75.46/showthread.php?p=1062762#post1062762)

[rock_ally]

I think its partially getnetic. it has to be

[Fritz Fuddles]

I'm neither scientist nor Vulcan, but I'll give this one a shot. I compare the magic born of JKR's world with the Jedi of Lucas' galaxy far far away. If you understand Star Wars then you'll understand my rationale.

Maybe there is some logical explanation to it all, maybe not. To me it's just fun to dream what life would be like if I had either one of these abilities.

[Jessica]

Until the threads get merged I'll re-post this here as well

Ooooh. Yet another opportunity to present my magical gene theory.

To properly undestand this theory you need to understand that some genes (for example baldness) can become dominant or recessive due to the presence of another factor.

In baldness this factor is testosterone. This is why baldness is far more common in men than in women. Baldness is dominant in the precense of testosterone and recessive without it.

Therefore in a man (B = bald, H = hair (not bald))

BB = bald
BH = bald
HH = not bald

In a woman however,

BB = bald
BH = not bald
HH = not bald.

Okay now assume that the factor for magic is the presence of magic. i.e. if a child is raised in a home where magic is present the Magic gene becomes dominant. If a child is raised in a home where magic is NOT present the Muggle gene becomes dominant.

Therefore in a Magic family (W= witch/wizard (magic gene) M=muggle (non-magic)

WW = Magic
WM = Magic
MM = Squib

But in a muggle family

WW = Magic
WM = Muggle
MM = Muggle

Ummm. .yeah. I AM a geek. Why do you ask?

[squirpy]

it can't be like a virus. then muggles who live near wizards would turn into wizards.

I don't think this thread is the same as the Muggle-borns/Wizards thread.

[Shauna]

The thing that is taking away from the magic is its illogical nature. And remember if you think magic must have something to do with genetics you are on my side no need to argue.

Yes, there is a need to argue, because I have said twice now that magic has nothing to do with genetics. I didn't even know you had a "side" until just now. I said that JKR based magic's hereditary nature off of genetics, but that whether someone is actually magical or not has nothing to do with DNA. There is no gene for it in the actual DNA makeup, per JKR. I cannot possibly make myself clearer than this.

Please stop putting words in my mouth.

Shauna

[morgan le fay]

while i agree with emerald eyes, heres some stuff from the HP Lexicon to back up you genetics people:


What is magical ability? The wizards in HP take the answer to this question for granted, but, being Muggles, we don't. What wizards do say, however, gives us a few clues.

Most wizards speak of magical ability as an inherent talent that appears in humans in various degrees. We find this out for the first time when Hagrid informs Harry that he is a wizard:

"I'm a *what*?" gasped Harry.
"A wizard, o' course," said Hagrid, sitting back down on the sofa, which groaned and sank even lower, "an' a thumpin' good'un, I'd say, once yeh've been trained up a bit. With a mum and dad like yours, what else would yeh be?...." (PS/SS, Ch. 4)

Which gives us two more clues to the puzzle, that magical ability is genetically linked, and that the talent can be cultivated to focus the power of the wizard.

.......

And similarly, Ron explains what makes Argus Filch a Squib:
"Well -- it's not funny really -- but as it's Filch," he said. "A Squib is someone who was born into a wizarding family but hasn't got any magic powers. Kind of the opposite of Muggle-born wizards, but Squibs are quite unusual. If Filch's trying to learn magic from a Kwikspell course, I reckon he must be a Squib. It would explain a lot. Like why he hates students so much." Ron gave a satisfied smile. "He's bitter." (CoS, Ch. 9)

This would suggest that the wizarding talent gene is recessive (or linked to more than one gene, or some other explanation), if apparently magic-less people produce a wizard and wizards rarely produce anything but more wizards. According to Ron, Squibs and near-Squibs use such things as Kwikspell courses in the attempt to make up for what powers they lack, probably not with much results. Which suggests again that training is meant to focus and polish magical people's powers, not bring them into being where they did not exist before.

this squib explanation agrees with jessicacarstens' baldness analogy. squibs are like bald women: they exist, but theyre hardly common at all. although there are probably more bald women in the world than squibs in the magical world, consider the likely population of magical folk to the population of muggle folk. proportional perhaps?

[Lincoln]

She said it doesn't have to do with DNA, but that doesn't preclude a sort of magical genetics that doesn't involve genes at all. Perhaps something attached to a person's spirit or something like that?

[filius]

I suppose it could be. But only in wizarding families even if it misses a few kids from time to time to produce squibs :p. But in muggles, i think it is very rare and all up to luck.

[roz]

I like jessicaCarsten's but I think that we are all being too simplistic. I suspect that there are several factors which when combined trigger magical ability. I see it as a question of nature vs nurture.

First of all there is probably some in built tendancy in muggles to be resistant to magic. It is only if you are not born with this tendancy that you have the potential to be a wizard. Now that tendancy could be genetic but it might not be. It also isn't neccessarily a switch that is on or off it could be a sliding scale. This is the nature bit.

Secondly, the nurture bit, I suspect that you need to be exposed to magic as a child to trigger your own potential. In Harry he lived as a muggle for many years but as a baby he was exposed to magic. In Ron he grew up in a magical household. I am not sure how the muggle borns at Hogwards were exposed to magic, perhaps there are areas in the country where the magical background noise is high enough to unlock the potential in muggle borns who are particuarly sensitive to it.

There could also be a third factor. There might be an emotional trigger too. In PS Hagrid asks Harry if strange things hadn't happened when he was angry or frightened. This might explain why Neville was such a late bloomer. He was so coddled by his grandmother that he had never been really frightened until his uncle dropped him out of the window.

I think that there are no late starters at Hogwarts because there is a point after which the potential is no longer there. If you haven't unlocked the magic within you by a certain age it can never be unlocked. Rather like the people who have the potential to be great sportsmen at 10 but because they don't do anything with that potential they never attain the level they are potential of.

OK, I am not sure how clear that is but hopefully you can understand what I mean.

Roz.

[LowKi]

The books about wizards, I dont know why your getting so hung up on logic in a book thats quite blatantly grounded in the illogical side of everything.

[Bilius Weasley]

I tend to think, as was described earlier, that being magical is something that you "catch". Being born/raised in a magical household would greatly increase you chances of being "infected" with this magical bug. We see that there is quite a bit of magic occuring all over without muggle knowledge (Knight Bus driving around, Platform 9 3/4, etc.) that a muggle born child could easily "catch" this magic bug without direct contact with a magic family. After you are born, or reach a certain age, it could become increasingly difficult to catch the magic bug (although perhaps not impossible, if we do see a muggle gain magic powers as is hinted at). Squibs happen just as there are people who don't get sick when everybody else who eats rotten food does.

One thing that I'm curious about is why there are so few (or so it would appear) wizards/witches. If there are muggle born wizards, and even squibs know about the magic world, then the magic aware population should always be growing over the years. The Weasleys prove that wizards can (and do) procreate as fast a muggles. We know that wizards live longer and it would appear that their "healers" are more efficient than muggle doctors. All this would suggest that, given time, the magic population should overtake the muggle one. Major muggle/wizard or wizard/wizard wars should be the only thing that decreases the magic population. If wizards were common enough 1000 years ago to warant building Hogwarts, why isn't there the need for 10+ more Hogwarts type schools for England in the current time?

[Demetri]

If it was something you catch then how is Hermione such a good witch, despite having little to no contact with magic. And how come Harry is still better than Neville or Ron or others.

So if it is a combination of it being caught and then once you have been exposed to it you become good based on something inside you then it is still based on genetics.

Genetics have to play a part in it, there really isnt another logical way unless JKR wants to intervene (visibly and not too gracefully might I add...) in her own books to kick logic out which would seriously disappoint me.

[squirpy]

if being exposed to magic is what makes you magical, then how does that magical quill write the names down as soon as the babies are born. A muggle like hermione would hardly be exposed to magic at birth.

[RyuKid]

I think genetics gives you a better chance.
Maybe destiny chooses if you can be a wizard/ witch (like Hermoine).
Or its up to the Headmaster to see if your worthy of being a wizard (like Hermoine, when Dumbledore gave her an acceptance letter)

[Demetri]

If that is so then it is still genetic which is basically my point. I am simply saying logically JKR made a boo boo.

[TaraBrady]

Maybe with Muggle-born students, their parents' open-mindedness or temperament affects their susceptibility to the magic 'virus.' Some muggles are clearly better equipped to deal with magic than others, so maybe the parents mindset affects the unborn witch/wizard's environment in such a way as to cultivate the little magic spark in them, like having enough oxygen to feed a flame.

It might help to think of magic less as a virus and more as a force, something along the same lines as radioactivity. We know there are no other magical people in the Privet Drive area, which seems to be a profoundly mundane environment. But in other areas there might be sufficient levels for magic to take hold in some unborn kids. From there, the sort of parents they have determines whether the magic grows or dies in them, so that by the time they're born, the ones whose families are the best candidates for a magical child have developed magic.

This would make magic something that almost evolves in muggle families; growing up in an imaginative household (I'm picturing ones with lots of books, not much television, parents making a big deal of things like Halloween and telling you stories at night) makes you a good candidate for producing a witch or wizard. You marry someone of a similar background/mindset, and set up a household where magic can flourish. This makes both the parents and the new wizards/witches better able to deal with what must be a rather severe shock, and allows them to better adapt to a completely alien world.

I know I'm putting a lot of thought into something that's essentially a non-issue, but like I said before, Jo said it's not genetics, and I'm determined to make that make sense to me. Forcibly, if necessary.

[FawkesFire]

what a fun idea.

if magic was genetic, it's more probably a polygenic trait. that is, it is controlled by more than one gene.

mendellian traits (hitchhikers thumb, attached earlobes, widows peak, etc) are controlled by only 1 gene, cannot explain the emergence of squids AND muggleborns.

for example: if magic were recessive (needing two copies of the same gene m to make a wizard) ...it would be possible for two muggles of a genetic makeup (Mm and Mm) to create a wizard child (mm). However, squibs would NOT be able to arise from a pure blood wizard family, as two wizards mm and mm CANNOt make an Mm or MM. Only a muggle (Mm) and a wizard (mm) could make a squib...but that doesnt really fit the definition, does it?

It basically works the opposite way if magic were dominant...with no possibility for muggles to bear wizard children.

So, the only possible explanation is that, like eye color, skin color, and other polygenic traits, magic is controlled by many different genes interacting. the numberous different combinations giving rise to muggle-borns, pure bloods, and squibs alike (possibly with varying levels of magical ability).

[leoguy72388]

clearly magic cannot be dominant because then muggle borns could not exist. But it seems strange that is it recessive. Look at the example of lily and petunia. Do we know if their parents were or weren't wizards? No we don't know. We do know however that atleast one of them was NOT a wizard otherwise it would be impossible for petunia to not be a wizard. Of course the parent that wasn't a wizard must have been heterozygous otherwise it is impossible for lily to have become a wizard. Lets call muggle M and wizard m. So far we have that one parent was Mm. Now the other parent could have been mm or Mm. We do not know. I think it is possible to assume though that the other parent was Mm because petunia says that her parents were so proud to have a witch in the family. Therefore we have a punnett square that looks like this:

| M | m |
---------------
M | MM | Mm |
---------------
m | Mm | mm |

This means that there was a one in four chance for them to have a witch. Of course this is all simply speculation and probably not true because JKR has stated that it is not involved in the dna. It is interesting though to look at one of the bigger assumptions made in this: that petunia is not a witch. I think JKR has made it pretty clear that she is not a witch and is pretty envious of lily but it seems like the things that appear clear in our eyes are the things JKR loves to trick us with. In the fifth book we find out a lot more about petunia. She has made a pact with dumbledore and appears to know quite a bit about the magical world. Why would she have made a pact with dumbledore to take care of harry if she pretty much hated her sister and harry was the last thing she wanted. The dursleys are made out to be very very horrible people but I think it is possible that petunia isn't as bad as some think she is. She seems to just be unhappy with her life. In the movies ( I know I know don't compare the books with the movies) she looks unhappy and looks very torn during the scene where the aunt blows up. I am really not sure this is all speculation but I think that petunia definately will play a much bigger part in the following books. Perhaps voldemort will try to go after her thinking that if he kills her Lily's love that protects harry will be weakened?

[netsirk]

clearly magic cannot be dominant because then muggle borns could not exist. But it seems strange that is it recessive. Look at the example of lily and petunia. Do we know if their parents were or weren't wizards? No we don't know. We do know however that atleast one of them was NOT a wizard otherwise it would be impossible for petunia to not be a wizard. Of course the parent that wasn't a wizard must have been heterozygous otherwise it is impossible for lily to have become a wizard. Lets call muggle M and wizard m. So far we have that one parent was Mm. Now the other parent could have been mm or Mm. We do not know. I think it is possible to assume though that the other parent was Mm because petunia says that her parents were so proud to have a witch in the family. Therefore we have a punnett square that looks like this:

| M | m |
---------------
M | MM | Mm |
---------------
m | Mm | mm |

This means that there was a one in four chance for them to have a witch. Of course this is all simply speculation and probably not true because JKR has stated that it is not involved in the dna. It is interesting though to look at one of the bigger assumptions made in this: that petunia is not a witch. I think JKR has made it pretty clear that she is not a witch and is pretty envious of lily but it seems like the things that appear clear in our eyes are the things JKR loves to trick us with. In the fifth book we find out a lot more about petunia. She has made a pact with dumbledore and appears to know quite a bit about the magical world. Why would she have made a pact with dumbledore to take care of harry if she pretty much hated her sister and harry was the last thing she wanted. The dursleys are made out to be very very horrible people but I think it is possible that petunia isn't as bad as some think she is. She seems to just be unhappy with her life. In the movies ( I know I know don't compare the books with the movies) she looks unhappy and looks very torn during the scene where the aunt blows up. I am really not sure this is all speculation but I think that petunia definately will play a much bigger part in the following books. Perhaps voldemort will try to go after her thinking that if he kills her Lily's love that protects harry will be weakened?

just a point of clarification about the chances. the chance, following your above model, is 1/4 for each child independent and irrespective of what the other children are.

also, if you know not to compare the books with the movie - then why?
if you read the passage when marge blows up, petunia is just about horrified. she's terribly conflicted in book 5 when mr. dursley throws harry out. she never says anything until the howler arrives, but she appears to be conflicted.

i think these feelings are due to the fact that she had little to no love for her sister and thus the feelings go on to harry. however, as dumbledore has explained, she is aware that her sister died for harry to survive and that she is key for harry to remain alive.

this being said - i'm not sure i follow your argument connecting genetics of magic to petunia feeling conflicted. care to flesh it out s'more?

[leoguy72388]

there really was no connection between confliction and genetics ... just random stuff that i started thinking about ... although she clearly is conflicted ... i am really not sure about petunia's role in the main plot but i am sure there must be one because JKR doesn't start making someone a bigger character without reason this is also why i think neville will play a major role and DEFINATELY luna because JKR brought luna into it ... im thinking harry's love interest .... tangents >____<

[GabrielTurner]

I never liked to mix magic and science never any more than mixing religion and science. But like religion is with science so is magic. Magic is a type of supernatural that can not be explained by magic. There may be sciences of magic that require magic, but I dont think a muggle could science out magic. It'd have to be a wizard or witch sciencing out magic, which is really impossible...

All too confusing. :rotfl:

[netsirk]

very interesting indeed about love interests - but unless you can connect them to magic and genetics, then it does not really belong on this thread:)

[netsirk]

I never liked to mix magic and science never any more than mixing religion and science. But like religion is with science so is magic. Magic is a type of supernatural that can not be explained by magic. There may be sciences of magic that require magic, but I dont think a muggle could science out magic. It'd have to be a wizard or witch sciencing out magic, which is really impossible...

All too confusing. :rotfl:
birth and the magic of life are explained by science
the creation of the universe is largely explained by science

x-men, although comic book, are explained by science

what makes jkr's world so different in your op?

[leoguy72388]

what makes jkr's world so different in your op?

I agree, the world of HP is not above science, although it may not be scientifically correct due to the fact that it was not created to be scientifically correct. It is a fictional story and just that anything farther that we make it is simply hypothesizing and is false until proven correct. Some people just need to lighten up, is it really important to know that science and magic don't mix? We are mixing it anyway and just because we are mixing it doesn't mean it is true, if you don't like what we are doing. Tee Hee im in a bad mood so i am being mean :evil:

[Voldie_Mort]

Maybe it's not extactly DNA... but maybe it's like being born white to white parents. As for Squibs and people like Hermione, it's like an albino African

[drdementor]

Ooooh-kay.

So, on the one hand, we have the surprising statement from Jo that magic has nothing to do with DNA. Her statement surprised me because I had been having a lot of fun deciding how the genetics of magic worked, and had finally decided that there were about seven different alleles, and to be a wizard you needed a certain pattern of dominant and recessive alleles. Miss Jo blew that and all other DNA debates out of the water, and a good thing, too. Can you imagine the interviews after book 7?

Me: SO, Ms. Rowling, we're all wondering, if 2 Half Bloods marry, what are the odds that their children will be squibs?

Jo: Oh, I don't know, they'll mostly be wizards.

Me: Hmmmm. Yeah, I thought as much. So, what do you think of this complicated punnett scheme? Am I right in saying that heredity through magic involves seven alleles? I wasn't sure about the seven, but I thought it an appropriate number. Would you mind filling in this little chart, here? And maybe calculating the probabilities based on the population size in England?

Jo: (bats me over the head with my punnett chart and runs for the hills)

And on the other hand, we have a bunch of people saying that since magic obviously follows SOME hereditary pattern, since most muggles have muggle children, and most wizards have wizard children, the only way for that heredity to take place is through genetics (NOTE: GENETICS, in current scientific understanding, implies DNA or RNA).

The following is a quote suggesting a logical alternative:

...But just one teensy little idea, that I'm ashamed of because I hate and am awful at science, but here goes - could magic be like a virus? You know how in some people they aren't effected by a virus, but when they pass it on to others, like their children, their children are effected? And wizards naturally keep on passing down the virus to their offspring, but ever so occassionally a child has a natural immunity - a Squib. Obviously it wouldn't be contagious to other people, otherwise there'd be adult wizards and so forth popping up all the time after rowdy office Christmas parties. :p

And someone else also came up with this idea, because Star Wars Episode I uses it as an explanation for Jedi powers.

So, anyway. This "virus" or "freaky living organism inside you" in Star Wars is based in science and logic, so right on,
Bouncing Ferret. The following are two examples of organisms that have symbionts transmitted at conception:

1)Aphids (bacteria that grow INSIDE aphid's cells)
2)All eukaryotic cells (mitochondria and chloroplasts have separate DNA)

These symbionts must be transmitted for the organism's survival. We can't live without mitochondria, and aphids need their bacteria to digest food properly.

Now, what if there were a "magical" symbiont that theoretically was passed through sperm as well as eggs. This would NOT be a genetic heredity, because although the symbiont in the "muggle" world would have DNA (or RNA if it's a virus), it would not be included in the human genome, so Jo could get away with her little statement. Well, the symbiont would not be essential to life; muggles survive and have children, after all. So, there's less selective pressure to ensure that each egg/sperm contains the symbiont. Every so often, a child is born to magic folk that is a squib; sadly, the symbiont was present in neither of her parent's gametes. What about muggles having wizard kids? Well, say that the mutualist can exist in nature (maybe in magic plants or something) and every so often infects a muggle. That muggle then has a chance of passing on the symbiont to her children.

NOTE: I don't think that Jo has this scenario all planned out, or ever will use this as an explanation. I'm just using this example to explain that even if she were to use a logical, scientific explanation for magical heredity, she can throw DNA out the window if she so desires. Especially if she says that the symbiont is a sub-atomic magical spirit-like organism that bonds to iron and is therefore actually in the "blood" of wizards.

Secondly, although several fantasy authors have used scientific-sounding explanations for their characters powers, Jo has never done so. That's fine by me, since usually the "scientific" explanations of fantasy authors require the "turn off your critical thinking" button. Take X-Men, one of my favorite fantasy series. The explanation for the X-Men's extraordinary powers? They are mutants. Wow. And every mutant has extremely different powers. THis is not, all of a sudden there are a bunch of kids running around shooting lazers out of their eyes, and here's the locus of that allele, and here's the protein it codes, and here's its result in the human body, and here's how it's transmitted. No, the X-Men "mutation" statement is in fact as simplistic as saying it happens because of "magic." Even the characters with similar powers, such as telepathy, use different forms of telepathy and have other powers as well in varying degrees. That's not to bash the X-Men. I like them a lot. I'm just saying that when you probe deeper into the "science" of the X-Men, and most other fantasy worlds, you find a magic black box.

Back to Jo. Has she ever written why the human body, apparently so fragile, can take being blown up and expanded like a balloon, then popped? Has she ever said how one object can be turned into another composed of entirely different materials? I mean, I can understand a sweater being transfigured into a hat, but a hedgehog into a pincushion? A living, breathing animal into a cotton-stuffed bit of cloth? And why exactly does magic cause electrical objects to malfunction? Some authors would try to explain this stuff using science; they might explain that certain electron orbitals cause a "magical" energy, that when tapped, can stretch the fabric of reality. And some people would actually buy that as more realistic and logical than just saying it's because of magic.

I'm not saying Jo is illogical or that her world doesn't make sense. The human relations and characters are very realistic; she writes the best bunch of teenage kids I've ever seen. The messed-up politics is logical, given the characters running the Ministry. Even her magic follows certain rules that she has made up. One of those rules is that heredity in magic does not involve DNA. There could be a "logical" alternative to DNA that Jo may suggest, but I think she will avoid the issue altogether since she isn't a scientist and doesn't care about appeasing them.

I mean, c'mon. She has dementors going around sucking people's SOULS out; if that's not unscientific, I don't know what is.

-Dr. Dementor

[acidoz]

All right, that was a lovely scientific ramble. I could have written it myself. Now I'm going to suggest my own explanation. It is "the best hypothesis that fits the facts" as far as I can see, and I have 20/20 vision...
OK, I propose that magic ablility is not in any way genetic. I suggest it is a quality of the soul. A lot of magic is simply enganced perception or ability, control over other matter and living things. I therefore suggest that magic ability is kind of like having a soul that is more sympathetic to nature and "invisible" things than the average human. That is why someone who has trained themself to be more sympathetic to their inner dog can turn into one, and can cause a heavy case to move by itself: he simply needs to get in touch with the fundamental nature of the object and direct it.
Another thing I'd been interested in is the fact that objects can be moved without force being applied to them. This is against the laws of thermodynamics, so I thought that the force in question is in fact being supplied by the body of the mage, so that if they did it long enough they'd be absolutely exhausted. Same applies to creating sparks, magical shields and enchanting objects. However, this doesn't hold up because "everlasting fire" would die when the mage who created it did.

[codswallop]

And on the other hand, we have a bunch of people saying that since magic obviously follows SOME hereditary pattern, since most muggles have muggle children, and most wizards have wizard children, the only way for that heredity to take place is through genetics (NOTE: GENETICS, in current scientific understanding, implies DNA or RNA).drdementor

I am guessing that witch/wizard and muggle(no magic) usually produce witch or wizard, Voldemorte, Seamus....I am not sure about Tonks, it says her father is muggle-born and I am assuming that he is magical but born to muggles.

[Wab]

Perhaps it was something that she didn'y really give a lot of thought too. Muggles can occasionally have magic kids and vice versa, she thinks, nifty plot device and leave it at that.

[Boneca]

This is a completely useless discussion, therefore perfectly to my liking! :p

I've studied genetics, and I don't find it particularly hard to explain magical ability as it appears in the book by using genetics. I'm quite positive it said somewhere in the books that only children who are magical enough are admitted at Hogwarts - this statement clearly shows that we are dealing with a cumulative trait, with probably three or more genes involved. That may mean that having one "magical gene" is not enough, you'd need two or three for it to show at all, and only if you have four or five (or however many genes are involved) "magical genes" active would you be a powerful witch/wizard.

As we know from the books, magical ability is partly genetic, partly an aquired trait, i.e. it can be "refined" if the child is trained properly. Therefore, a whole lot of muggle children could easily have one, or perhaps even two "magical genes", without having a clue about it. This may cause them to be slightly magical (weird), but is not enough to attend Hogwarts. Only if, say, three "magical genes" are active would the child be so obviously magical that it would need an introduction to the wizarding world.
On the other hand, if a child raised in a wizard family would have only two "magical genes", they would still be able to refine their skill and learn to use their limited ability in order to become wizards anyway (Neville, anyone?).
In pureblooded families, both parents would have at least one magical gene, making squibs very unlikely, but still possible, since the parents may have different magical genes active and could therefore possibly both pass on the inactive alleles for their respective magical genes.

The inheritance of polygenetic traits are in general quite hard to predict in individual cases (but fine to predict on a population level), which seems to be the case with magical ability in the HP books.
As for Jo saying that it has nothing to do with DNA, my only thought is that she probably doesn't know what DNA really is. And only nerds like us care anyway. :rotfl:

BTW, somebody had a theory on a particle infecting mitochondria - you know mitochondrial DNA is only inherited from the mother, which would mean that only children who have a witch mother would be magical, no matter who the father is. And it's still DNA.

[drdementor]

This is a completely useless discussion, therefore perfectly to my liking! :p

BTW, somebody had a theory on a particle infecting mitochondria - you know mitochondrial DNA is only inherited from the mother, which would mean that only children who have a witch mother would be magical, no matter who the father is. And it's still DNA.

Yeah, direct inheritance through mitochondria wouldn't work, would it? And it does have to do with DNA. But what if it was just LIKE mitochondria, in that it's an independently replicating something (like maybe a weird self replicating protein similar to a prion but not deadly) that could be passed on in both sperm and eggs?

[Boneca]

But what if it was just LIKE mitochondria, in that it's an independently replicating something (like maybe a weird self replicating protein similar to a prion but not deadly) that could be passed on in both sperm and eggs?

Hm, not likely but possible. Prions are strange things! Still, a virus-like protein would infect everybody equally much, so it wouldn't explain why some people would be more magical than others. Unless of course some gene or other gives a full or partial immunity to infection by this protein (which would again mean that it HAS to do with DNA).

[DragonBlk17]

I think that magic is a gift for those who are muggle-born.

But for the purebloods and half-bloods it's genetic.

[Danluver182]

I always thought it was passed on through DNA as well. Like Hermione...she has muggle parents but I always thought it meant that somewhere down the line she had a wizard or witch in her family and she just happened to pick it up. Maybe we're wrong. It's JK's world and she knows best I suppose.

[Kimmetje]

I must agree with Danluver182 that there might have been a witch far away in the family that ended the bloodline, skipped five generations and than ended up with Hermione or a other mudblood.

With purebloods and halfbloods it's definitely genetic as the magic passes itself on. If the magic doesn't get passed on that someone is a squib.

[Serpentine]

Just on a short note... there's a new essay on MuggleNet, about how magic may have come up, its relations to history, and - possibly recessive - genes passed on. Definitely worth the read. (Though I like the ideas with a magic virus or the mitochondria too. You guys really think it through, keep up the good work! :tu: )
The Origins of the Wizarding World (http://www.mugglenet.com/editorials/editorials/edit-ashley.shtml)

[HarryPotter]

I think it is not genetic, although it acts as if it was...

[squirpy]

Maybe it's like athleticsm (sp?), often kids of athletes are quite athletic. Sometimes you get a great athlete out of the blue. And sometimes you get children of athletes who aren't athletic. And there are degrees of athleticsm. It can be refined through practice. Sounds pretty similar to me.

[Nephel]

Neville's parents were aurors, i.e powerful wizards, and Neville doesn't really live upto his parents talent. I don't think Magical Ability is genetic.

[maritoy]

Here's my genetics take on the Magic blood. Now I believe that being magical is a dominant trait. I know, but what about the muggles??? Well, there are many dominant traits in humans, that aren't expressed in the majority of the population. There is a disorder that causes shortening of the fingers, and that is a dominant trait. This also explains why most Wizarding families are just that, wizarding. Now here's my take on squibs. The squib trait is recessive to the dominant magic trait. So say a wizard is magical, but has an allele for squibness, and he marries another witch who has the same recessive squib allele. Both are magical, but could have a squib child.

M= magical allele
m= squib allele

Mm X Mm
MM, Mm, Mm, mm

So these are their children. Three are magical, but one is a squib.

Then I believe that the muggle-born witches and wizards are just lucky to have a random genetic mutation. I haven't seen anywhere of two squibs having a magical child, but if that's happened, and I've missed it, kindly discount thie entire theory.

[Shrewd]

I fleshed out this theory pretty well on the Layers thread a few days ago:

My theory is:
Wizarding is dominant. Using common notation, where a lower case letter is recessive.
Muggles are ww
Wizards can be Ww or WW
If two magical parents have a child, that child will be wizarding. If two muggles have a child, that child will be a muggle. That's the pure Mendelian genetics of it.
Adding in mutation of genes, assume that the Muggle gene is the 'normal' one. (Perfectly normal, thank you very much. :D ) A mutation in one of the w genes would cause the child of two Muggles to be a wizard; they'd be Ww.
So now we've got Muggles, Wizards, and Muggle-borns. A squib would then happen in one of two ways -
If two parents with the genes Ww had a child, with each child there would be a 25% chance of it being a Squib.
There is also a slight chance of back-mutation, meaning that while the child would normally have inherited the genes Ww from his or her parents, the W gene mutated BACK and has become ww.

I can't remember if it's been discussed in Layers yet - it probably has - but what about the fact that a lot of the strongest wizards we see are either half-bloods or Muggle-borns? Harry, Voldemort, Lupin, Hermione... Mendel noticed that when he crossed TT (tall) with tt (short) pea plants, the resulting plants (Tt) were taller than even their tall parents. I can never remember what this effect is called, but that might explain this rather odd phenomen... or not.As far as why they're not as common... I have a theory related to inbreeding that has something to do with it. I still haven't found a place to put it yet... but the other thing is that many populations come to equilibrium... and we never find out how many magic/muggle marriages produce magical children -- and in what numbers.

[leoguy72388]

Neville's parents were aurors, i.e powerful wizards, and Neville doesn't really live upto his parents talent. I don't think Magical Ability is genetic.

Well I believe neville will prove himself. He had a slow start at hogwarts but I think things will only get better for him. He really needs some incentive. I mean what is he working toward. Oh yes I am sure his parents that barely recognize his would be SOOOO proud (notice sarcasm). Maybe something will happen that will give him a reason to try harder. And of course he isn't the best student (or at least not from what we have seen). I am sure he will find something that he is good at.

[mel]

I haven't read the whole thread yet, but here is my theory:

First of all, it's a recessive trait.
M = muggle allele (dominant)
m = magical allele (recessive)

MM = pure muggle
Mm = muggle carrying magic allele
mm = magical

The big obstacle to this reasoning is half-bloods. I was assuming that half-blood meant a person was heterozygous for the wizard gene (Mm). But that would make them muggle. So my explanation is that there really is no such thing as a truly "half-blood" wizard. You either are magical or you aren't, you can't be mixed. JKR actually backs this up on her website (http://www.jkrowling.com/textonly/faq_view.cfm?id=58): "The expressions 'pure-blood', 'half-blood' and 'Muggle-born' have been coined by people to whom these distinctions matter, and express their originators' prejudices." There may be no genetic basis for halfblood/mudblood, just like there is no genetic basis for race - it only matters to the people who discriminate.

Another obstacle to this was the presence of squibs. Two recessive genotypes (two wizards) should only be able to produce recessive offspring (a wizard). Well, squibs seem to be rare (the vast majority of wizard offspring are magical), so I consider squibness to be either a genetic mutation or a defective gene. Perhaps there is some other gene that is interfering with the expression of the magical allele, or the gene itself just mutated. It happens in real life (though infrequently), so it can happen in the wizard world (though infrequently).

The rest all falls into place:

MM x MM = all offspring are MM (full muggle)
MM x Mm = 50% MM, 50% Mm (muggle carrier)
Mm x Mm = 25% MM, 50% Mm, 25% mm (this last one would account for muggleborns - this means muggleborns have some wizarding ancestry, however distant)
Mm x mm = 50% Mm, 50% mm (what Malfoy would call "half-blood")
mm x mm = all mm (pureblood)
mm x mm = non-magical mm (genetic mutation/defect - squib)

EDIT: This scheme would also account for the frequency of muggleborns vs. squibs, something that some of the other theories don't seem to consider. Squibs are much more unusual than muggleborns, and my theory would explain that.

[Jessica]

Did you read my varying dominance idea? It's the same thing with baldness. It's donminant with men and recessive with women due to the presence or absence of testosterone.

[mel]

Yes, I read it, it's a very good theory. :agree: Really they both could work... although forgive me if I'm partial to my own. :blush: It explains the frequencies of squibs vs. muggleborns better, I think. It seems to me that muggleborns are much more frequent events than squibs, but they would have equal occurrence under your theory. However, we don't really know the frequencies of such events, so we can't be sure. :)

You think like me! :D

EDIT: Someone in this thread also pointed out that the Magic Quill records who is magical/nonmagical at birth. Yet for heterozygous genotypes, their magical ability would not be determined until they were exposed to the magical household - so how would the Quill know?

[SquibOnline]

I think it has to be

[Jessica]

Yes, I read it, it's a very good theory. :agree: Really they both could work... although forgive me if I'm partial to my own. :blush: It explains the frequencies of squibs vs. muggleborns better, I think. It seems to me that muggleborns are much more frequent events than squibs, but they would have equal occurrence under your theory. However, we don't really know the frequencies of such events, so we can't be sure. :)

You think like me! :D

EDIT: Someone in this thread also pointed out that the Magic Quill records who is magical/nonmagical at birth. Yet for heterozygous genotypes, their magical ability would not be determined until they were exposed to the magical household - so how would the Quill know?

Ooo. You got me on the Quill thing. Maybe it's an instantaneous thing. It there's magic in the room when the kid is born Poof! Magic!

But I disagree on the muggleborns are much more common than squibs thing. Look at the number of muggles vs. the number of wizards. If you look at the respective sizes of the populations then the proportions are probably about equal.

[Chievrefueil]

A lot of people seem to be trying to explain magical heredity through simple Mendelian inheritance, but are getting tripped up with the squibs. This type of inheritance is possible, though, with incomplete penetrance.

For example, if the magical trait is recessive, it would follow this pattern:

MM, Mm=muggle mm=wizard

MM X MM --> all muggle children
MM X Mm --> all muggle children
Mm X Mm --> 75% muggle children; 25% wizard children
mm X mm --> all wizard children

So, a squib would be ww, but have almost no penetrance of the magical trait (even though they had the "gene" required for the trait, it is not expressed; thus "incomplete penetrance" of the gene). This could also explain the variability of innate magical skill among the wizards. Incomplete penetrance would most likely be due to the effects of other "genes" on the expression of the magical gene. I point this out because the liklihood that magical ability is related to more than one gene has already been suggested in this thread.

Another thing to point out is that, while 25% wizard children produced by some Muggle parents may seem like a lot, the actual number of wizard children born to Muggles depends on how many Muggles are Mm--and it's probably not that many.

Even though I said "gene" as a way to describe this, I like the idea that there's some other inherited factor not having to do with DNA.

[ikuko]

Can someone give an exact quote from JKR? did she say it has nothing to do with DNA or nothing to do with genetics? 'cause it's not the same, you know. First of all, there is a strong evidence that magic ability IS genetic (passes from parents to children). Absolute majority of children of wizards are magical. Most children of muggles are muggles. => its inheritable. There are two snags on the way: first, according to JKR it's not DNA (I hope this is what she said and this was in the first quote here that I read). No problem. There are other carriers of genetic information, such as RNA - as far as we know. There is lots we don't. Perhaps there is more carriers than these two, and some of them magical.

The second snag is that in most cases if at least one of the parents is magical, children are too, for as many generations as you want. Attached to this difficulty is the problem of muggle-born being more frequent than squibs. These two are the two sides of the same issue - the inheritance is non-sexual. I do not mean it is transferred non-sexually, only that it does not require half of the genetic info to come from one parent and half from another. As someone mentioned above, there is more to genetics then sexual procreation. Th mitochondria and some other organells are inherited through a non-sexual way, from the mother only. And they might be pretty important - mitochondria are the power-stations of the cells and in part define the strength and health of the body.

But it's not the case here. Regardless who is the magical parents, children seem to be magical. Even more interesting, it seems that if a family of muggles produced one magical child, it is rather likely to produce another (50% of known cases, Creevey brothers, but not Evans sisters).

So, what can be a solution? Someone has already mentioned an infection, viruses. Yes, they can be non-DNA based, but then any muggle in close contact with the wizards would contract some. But what if it isn't an infection as such, but a carrier of magical "gene" we do not know yet? Suppose it can be shared through sexual (or even a kiss) contact, remain in the body forever, but affect only an unborn child? Then it all fallf into places.

1. It is NOT a DNA.
2. All wizards have it and can not transmit it to non-magical partners.
3. Regardless what parent is magical, the child will be magical, too
4. The muggle partners of wizards will remain muggles
5. Very rarely something goes wrong and there is a mutation - a squib
6. Occasionally, a wizard would have an affair/a flirt with a muggle woman, perhaps even very innocent. It will not lead to anything, but when later the woman marries a muggle and has HIS children - they come out magical. Perhaps as magical as any wizards. Because the magic is transferred ONLY by that mysterious carrier, they have as much of it as a pure-blood.

[MoodyHarry]

Well, magical abilities must be genetic or in your gene's somehow.

That is why you have magical parents who have a squib as a child, or non-magic parents who have a magical daughter such as Hermione. There must be something in the genes of the individual to allow them magical powers.

It is assumed that magical powers cannot be learned, since Filch cannot perform any magic, even though he has parents who are able to do so. The ability to perform magic must be a genetic trait born with the child and potentially passed onto decendents.

Another speculation is that the trait can skip generations. For all we know, Hermione's past ancestors had some magic blood in the family at some point, and skipped a few generations before manifesting itself in Hermione.

Magical ability may also be a genetic mutation that occured in the human race in past generations and resulted in a magical community. In the animal race (including human), there are so many instances where some flawed DNA or genetic mutation causes a new physical or mental ability that most people do not have. Of course, if the ability is a mutation, it would be interesting to think about who discovered the ability in the past and improved and developed the skill.

[woop]

sounds like the xmen to me.

[Mrs Flamel]

For those of you interested in this topic, I highly recommend this Red Hen article for a bit of light reading ;): On Magic and Wizards (http://www.redhen-publications.com/Magic%26Wizards.html)

He agrees that even if magic isn't actually genetic, it behaves as if it were and can be analyzed as such. He proposes that there are a large number of magical traits that can be inherited and that a certain threshold must be met to be able to do magic. Read the article if you want to find out how a person can be a muggle-born squib. :huh:

Anyway, he approaches lots of the questions that have been brought up on this thread.

[Boneca]

So, what can be a solution? Someone has already mentioned an infection, viruses. Yes, they can be non-DNA based, but then any muggle in close contact with the wizards would contract some. But what if it isn't an infection as such, but a carrier of magical "gene" we do not know yet? Suppose it can be shared through sexual (or even a kiss) contact, remain in the body forever, but affect only an unborn child? Then it all fallf into places.

1. It is NOT a DNA.
2. All wizards have it and can transmit it to non-magical partners.
3. Regardless what parent is magical, the child will be magical, too
4. The muggle partners of wizards will remain muggles
5. Very rarely something goes wrong and there is a mutation - a squib
6. Occasionally, a wizard would have an affair/a flirt with a muggle woman, perhaps even very innocent. It will not lead to anything, but when later the woman marries a muggle and has HIS children - they come out magical. Perhaps as magical as any wizards. Because the magic is transferred ONLY by that mysterious carrier, they have as much of it as a pure-blood.

This is a very interesting theory, but I see one slight problem. How come Lily came out a witch while Petunia did not? Your theory would actually imply that their mother had an extra-marital affair after Petunia's birth!

[ikuko]

This is a very interesting theory, but I see one slight problem. How come Lily came out a witch while Petunia did not? Your theory would actually imply that their mother had an extra-marital affair after Petunia's birth!
lol. And why that would be impossible? What do we know about Harry's grandparents to assume that their marriage was idillic? <whispers> these things do happen...

On the other hand, we do not know if Lily was younger. Perhaps, her mother shared merely a kiss in a highschool with a boy wizard (and never knew who he was) and it was just enough for only ONE magical child.

[Mists_of_Avalon]

What about Hermione? Both of her parents are muggles. Either her mother had an affair (doubtful) with a wizard or her ancestral line skipped a few generations...

[ikuko]

What about Hermione? Both of her parents are muggles. Either her mother had an affair (doubtful) with a wizard or her ancestral line skipped a few generations...
Why? do you think Mr. Granger was the first man who ever came close to her? we just discussed the possibility of magic carrier being transferred through innocent contact, such as a kiss. And why in the world people assume that if there is little known about a family and they seem generally stable, then their life must be as plain and boring as cold poridge? The scheme "marry a virgin and never look at another" only fits for Quibber.

[voldelavie]

I'm sorry, it's kind of long-winded. You can skip and read my point at the end.

I've always thought of Potterverse magic as a sort of energy that surrounds everything, (or kind of like the "Force" in Star Wars) not as a trait that's passed down like hair color, height, eye color, etc... I think magical ability has more to do with the environment you're in. Take the Weasley's for example, I think the weasley children have the ability because they were in a place where magical evergy was present. I also think this works for half-bloods as well. Seamus was around someone (his mother) with a magical "aura". (And Harry had been exposed to enough magical power in his first fifteen months to last him a life time.)

I also think magical ability has something to do with how you see the world (my theory of muggleborns). Here, I look at Harry vs. Dudley. Harry has ability because he's had to get through challenges. He knows that while life is worth living it's also not fair. However, Dudley, being the antithesis of Harry, has no need for magic because he thinks the world is made solely for him. So, I think someone with a more realistic view of the world is more apt to be magical.

As for squibs, I don't know. I have a theory that ability is also based on one's willingness to believe. If you don't believe feathers can fly then "wingardium leviosa" won't work. I think this is what happened to Filch and Mrs. Figg. They just have a hard time visualizing magical things. (Even full blooded students are shocked at some of the things that happen at school.) Also, maybe the "energy" just didn't take with them. These things could go either way, I suppose.

My point being, I think magic is more congenital (environmental) than genetic (hereditary).

[Chievrefueil]

My point being, I think magic is more congenital (environmental) than genetic (hereditary).
I'm sorry, I hope you don't think this is rude, but I'd like to clarify what you said. Congenital means that you're born with it--it could be inherited, like hemophilia, or it could be environmental, like fetal alcohol syndrome.

You meant that you believe magic is entirely environmental. Do you mean that you also believe one has to be born with it (through being exposed to magic in the womb)?

[Tane]

Ummmm is magic genetic that is a difficult question to ask though I find it difficult to say yes it is as there is supposed to be a late blooming witch or wizard(I know the late bloomer thing again from me, I'm just obsessed by the whole issue) and if that is true then it can not be genetic. Well that is if say someone with no prior magic suddenly becomes magical because if the late bloomer just refers to some witch or wizard developing there powers greatly all of a sudden then magic can still be genetically determined.

Hard to say whether magic is something that a person gains through belief or if it is genetic as I do not think there is enough evidence out there to prove the question yet.

[voldelavie]

Do you mean that you also believe one has to be born with it (through being exposed to magic in the womb)?

Yes. I also think someone like Hermione, with her potential realistic worldview, made a good recipient for magical ability and was exposed to it somehow in the womb or possibly in early childhood.

[Mists_of_Avalon]

call me stupid or whatever you would like, but i still think that wizardry is genetic. for example, you dont just get your eyecolor from being exposed to someone with the same eyecolor. you get it from the begining of your cell structure and mixing of chromosomes from both parents. of course, its is all my opinion. none of us are wrong or right.

[nano]

So it's like the force then???? Thos little thingies (don't know what they were called in Star wars - but they could be measured) that are in your cells???

nano

[Mists_of_Avalon]

possibly....the thingys--whatever they were-- could function as cells or chromosomes when the baby fetus is first formed. ((it pays to pay attention in health class))

[mel]

I've always thought of Potterverse magic as a sort of energy that surrounds everything, (or kind of like the "Force" in Star Wars) not as a trait that's passed down like hair color, height, eye color, etc... I think magical ability has more to do with the environment you're in. Take the Weasley's for example, I think the weasley children have the ability because they were in a place where magical evergy was present. I also think this works for half-bloods as well. Seamus was around someone (his mother) with a magical "aura". (And Harry had been exposed to enough magical power in his first fifteen months to last him a life time.)Then how do you explain Neville? His parents and family were just as powerful as the Potters, and Neville has been able to spend his whole life with them. Yet he has only recently come into his own, after spending years submersed in magic at Hogwarts while still being bad at magic.

As for squibs, I don't know. I have a theory that ability is also based on one's willingness to believe. If you don't believe feathers can fly then "wingardium leviosa" won't work. I think this is what happened to Filch and Mrs. Figg. They just have a hard time visualizing magical things. (Even full blooded students are shocked at some of the things that happen at school.) Also, maybe the "energy" just didn't take with them. These things could go either way, I suppose.I suppose, but wouldn't that kind of prove your theory wrong? Obviously, there is some mechanism at work here, and if sometimes the energy just didn't take, then that would mean there isn't a mechanism, it's all just arbitrary. Filch, for instance, lives at Hogwarts 24/7, so he for sure believes in magic because he sees it every day. And we know he wants to be magical, because he was taking lessons.

If being magical was determined by the environment, Harry would be bad at magic and Neville would be good at magic. There would also be a lot more muggleborns and no squibs. I think it's pretty obvious that magic follows the rules of heredity. It's just a matter of figuring out how.


Ummmm is magic genetic that is a difficult question to ask though I find it difficult to say yes it is as there is supposed to be a late blooming witch or wizard(I know the late bloomer thing again from me, I'm just obsessed by the whole issue) and if that is true then it can not be genetic.Yes, it can. That is easily explained through gene expression. Many traits are the result of multiple genes, genes that are triggered by the environment, or genes that express symptoms that vary in severity, as seen in many genetic diseases - sometimes it's all of these things combined. This could explain the degrees of magical ability.

[Mrs Flamel]

If being magical was determined by the environment, Harry would be bad at magic and Neville would be good at magic. There would also be a lot more muggleborns and no squibs. I think it's pretty obvious that magic follows the rules of heredity. It's just a matter of figuring out how.
I agree. In JKR's world, magic just doesn't seem to behave as if it were influenced by environment. not that it's a bad idea, it just doesn't seem to actually work that way. Whether or not it's actually genetic, it behaves as if it were. I hate to say it, because I hate copping-out of a question like this, but: it's just magic!

To play devil's advocate, though: I think for Neville's case, his environment does play a role in the manifestation of his magical ability. He was born with whatever magical ability he was born with. But I think growing up knowing what magic did to his parents and living with such an authoritative grandmother has caused him to retreat into himself and fear and lack confidence in his own magical-ness. Not that he's not highly magical, but that he represses it or can't express it well because he has too little confidence.

[mel]

To play devil's advocate, though: I think for Neville's case, his environment does play a role in the manifestation of his magical ability. He was born with whatever magical ability he was born with. But I think growing up knowing what magic did to his parents and living with such an authoritative grandmother has caused him to retreat into himself and fear and lack confidence in his own magical-ness. Not that he's not highly magical, but that he represses it or can't express it well because he has too little confidence.Oh yes, I think confidence does affect magical ability. I think it is similar to talent - you are born with talent, but it must be developed if you are to be good at it. After Neville's parents were sent to St Mungo's, it seems like the rest of his family didn't really have any confidence in him. They seemed very disappointed and kept affirming that he was not good at magic. That has a huge affect on children. No wonder he has no self esteem. :no: He's never believed he could do it.

[Mists_of_Avalon]

not to repeat or anything, but magic is like asthma: youre born with it and its traits, you dont just accumulate it from the people around you. yes, some asthmas/magicalness can be stronger that others, or in magical form- powerful and less powerful witches or wizards. im not sure if i explained that right, but if you get my drift, you know what i mean. :tu:

[Auryn]

HI
I am new here but I think this is a really interesting thread and figured id put my 2 cents in.
magical families do have squibs- after all filch is one (sorry if someone hasnt read OFTP)

think about it another way though
it might be genetic but the apperance of magical genes might be spontaneous like many human genetic mutations
or it could be like in star wars
darth vader has a lot of the 'force' in his blood even thuogh noone else in his family or town does - he has a high chloromines (how ever u spell it count) but then his children have different levels- luke's is just as high as vaders but leia's isnt it

in the end though i think u sometimes do have to put logic aside and accept things for how they are and not try to rationalize it or put 'real world' rules into it
if you don't do that you can't accept flying brooms, and most of the other things that we love so much abotu these books.

that was it -more like 4 cents but hopefully it made sense

[Kain]

think it might have to do something with genes....

[Mists_of_Avalon]

most likely does, as I've stated before. :tu:

[petruchio]

OK, maybe someone stated this already, but it seems pretty obvious and pretty cut-and-dried as to magic's hereditary genetic nature. It's genetic, and it's a dominant gene. Otherwise, there would be no such thing as squibs.

Think about it: if both parents are wizards, and that child is born without magical abilities and doesn't manifest them by the age at which most wizards acknowledge that those abilities show themselves, the child is considered a "squib" and automatically becomes something of a pariah. This is known in evolutionary behavioral psychology as "non-norm genetic selection instinct."

An example can be seen in a deer herd: generally, the Alpha male of a deer herd is the one with the most symmetrical antler spread among similarly-sized males. Why? Simple: it's MORE NORMAL, in genetic terms, for a male deer to have symmetrical antler tines. Hence, asymmetrical antler tine patterns tend to be rejected by the herd, in favor of the "more perfect" specimen.

[Chievrefueil]

OK, maybe someone stated this already, but it seems pretty obvious and pretty cut-and-dried as to magic's hereditary genetic nature. It's genetic, and it's a dominant gene. Otherwise, there would be no such thing as squibs.

Think about it: if both parents are wizards, and that child is born without magical abilities and doesn't manifest them by the age at which most wizards acknowledge that those abilities show themselves, the child is considered a "squib" and automatically becomes something of a pariah. This is known in evolutionary behavioral psychology as "non-norm genetic selection instinct."

An example can be seen in a deer herd: generally, the Alpha male of a deer herd is the one with the most symmetrical antler spread among similarly-sized males. Why? Simple: it's MORE NORMAL, in genetic terms, for a male deer to have symmetrical antler tines. Hence, asymmetrical antler tine patterns tend to be rejected by the herd, in favor of the "more perfect" specimen.

How does this suggest that magic is dominant? If it is dominant, then it must be a new mutation in Hermione & the Creevey brothers. It doesn't seem very likely that a new mutation would pop up in a set of siblings, unless it's a very common mutation. And, it can't be that common or there would be many more witches & wizards than muggles. Also, a dominant magic gene doesn't really fit with the existance of squibs. If it was dominant, squibs would be magical. In your deer example, all the stags still have antlers. . .

[Mists_of_Avalon]

How does this suggest that magic is dominant? If it is dominant, then it must be a new mutation in Hermione & the Creevey brothers. It doesn't seem very likely that a new mutation would pop up in a set of siblings, unless it's a very common mutation. And, it can't be that common or there would be many more witches & wizards than muggles. Also, a dominant magic gene doesn't really fit with the existance of squibs. If it was dominant, squibs would be magical. In your deer example, all the stags still have antlers. . .

I agree...but it all boils down to the fact that some wizards/witches are more powerful than others (hence squibs). Its the genes that they are born with.

[hermy_weasley2]

My take on this:

Why should magic be genetic? Genetics are explained by science. Magic is meant to defy science.Things defy gravity and float in midair. Someone dies just because someone else waves a stick of wood and utters two little words. Borken things magically become whole again for the same reason. Science doesn't explain that. Why should science explain why someone has magical powers.


Side note: Read this post remembering that I know none of this real.

[Chievrefueil]

My take on this:

Why should magic be genetic? Genetics are explained by science. Magic is meant to defy science.Things defy gravity and float in midair. Someone dies just because someone else waves a stick of wood and utters two little words. Borken things magically become whole again for the same reason. Science doesn't explain that. Why should science explain why someone has magical powers.
You're right. But, for me the fun of discussing it is to determine a pattern that fits genetics (one of my favorite university subjects). Regardless of scientific "explanations," magic is clearly inherited. (I realize not everyone responding in this thread agrees that magic is inherited.)

[Mists_of_Avalon]

You're right. But, for me the fun of discussing it is to determine a pattern that fits genetics (one of my favorite university subjects). Regardless of scientific "explanations," magic is clearly inherited. (I realize not everyone responding in this thread agrees that magic is inherited.)

i happen to agree with chiev.

[Mrs Flamel]

not to repeat or anything, but magic is like asthma: youre born with it and its traits, you dont just accumulate it from the people around you. yes, some asthmas/magicalness can be stronger that others, or in magical form- powerful and less powerful witches or wizards. im not sure if i explained that right, but if you get my drift, you know what i mean. :tu:

You know, the comparison to asthma is quite apt! I got this definition from WebMD (http://my.webmd.com/hw/asthma/uf4635.asp):

The cause of asthma is unknown. Health experts believe that genetic, environmental, and immune system factors combine to cause inflammation that can lead to asthma and acute asthma episodes.
Your child may have inherited the tendency for asthma, making him or her more likely than other children to develop long-term (chronic) inflammation in the bronchial tubes, the airways that carry air to the lungs.
In some children, the immune system releases cells that cause inflammation in response to substances (allergens) that cause allergic reactions. Studies report that exposure to tobacco smoke or to allergens such as dust mites, cockroaches, and animal dander may influence asthma’s development.1 Asthma is much more common in children with allergies (atopic people), though not all children with allergies develop asthma.


OK, that's alot to read, but it basically says that you are genetically pre-disposed toward asthma, but environmental factors affect its development. This tends to even out the nature vs. nurture argument that's gone on around here. Even if magic isn't technically genetic, it is still inherited, and given the example of Neville, it can also be affected by environment.

[Mists_of_Avalon]

OK, that's alot to read, but it basically says that you are genetically pre-disposed toward asthma, but environmental factors affect its development. This tends to even out the nature vs. nurture argument that's gone on around here. Even if magic isn't technically genetic, it is still inherited, and given the example of Neville, it can also be affected by environment.

but roots do go to genetics. Glad to see that someone caught my drift. :tu:

[Sophie Patil]

it all makes sense, what you guys are saying. it is practically impossible for magic to be genetic. it can't be resessive and it can't be dominant. I think it's more like talent - this is a bad example but: let's say your parents are very good at maths, both of them. usually in families where the parents are good at maths, the kids are as well - purebloods. but also sometimes there is a kid who just really sucks at math (like me! ;)), even though it's 'in the family'. that'd be a squib. or a kid is extremely good at maths, even though the parents have no feeling for numbers whatsoever - muggleborn.

[Yrraine]

Gene expression depends on environment, which can include things like exposure in the womb to subtle things, and all the weirdness that goes into wiring the brain before and after birth. (Examples: the first cloned cat doesn't have the same coloring as her mother, because coat color depends on uterine environment; the chance of developing serious depression or schizophrenia if your identical twin does is 50%, not 100%.)
But I just can't twist it to work with genetics. It's clearly not recessive or dominant. If physics and chemistry can be tossed out, I don't see why genetics should stay in.

[xwillowelfx]

I would think that magic would be considered a recessive gene because it's pretty rare, but pure wizarding families almost disprove that. It seems to be strong in families that already have magic known but more random with muggle families. It's an interesting thought though.

[aggiefan1206]

Yes i would have to say it is but i guess some muggles have a recessive magic gene that shows up every once in a while that means her mom and dad would have had a magic gene so some other relative was a witch or wizard at one point. Its possible its not

[Drusilla]

I don't think it's genetic in the sense that a person can only be capable of magic if they have a witch and/or a wizard for a parent- the presence of Muggle-born wizards disproves that, though most offspring of magic-capable parents tend to be magical themselves. As aggiefan1206 says, the magical capability of Muggle-born children is probably thanks to a recessive gene (it's quite a possibility if there was a time when Muggles and wizards intermarried a lot, but then stopped).

[nano]

Seeing JKR does not seem to be a wiz on genetics I can hardly beleive Jo would even go to lenghs of explaining why some people are wizards and why some arent - after all the books are read by young people as well as old, so if Jo does give us an explanation it will hardly be a scientific one. So I guess we will never know if magic is genetically passed on or not.

nano

[StephyJ_83]

Maybe it's like the force . . . everyone has it, but it is a lot stronger in specific people. ;)

[Drusilla]

Well, she said on her site that magic is a dominant and resilient gene, so I'm guessing she had at least that much of the genetic structure of the wizarding world figured out- and magic is linked to a gene. I'm guessing it's recessive among Muggles, though.

[Lucybird]

This is from JKs site concerns squibs

J.K.Rowling Official Site

Section: Extra Stuff

SQUIBS

I have been asked all sorts of questions about Squibs since I first introduced the concept in ‘Chamber of Secrets’. 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.

therefore magic is genetic

[chupacabras76]

Absolutely, I think Jo's addition to the official site about Squibs is the clicher!

It would be great to know more about this, though. As Hagrid points out, even the oldest pure-blood families have some muggle blood in them if you look back far enough, so I'd love to hear from any biologists/geneticists about how this might work (it's far too long since my school days for me to remember anything about that recessive/dominant gene stuff!).

For example, how likely would it be that two muggles, such as Hermione's parents, who presumably do not (at least knowlingly) have any magical parents themselves, should have a magical kid?

Not central to the driving forces of the plot perhaps, but in a universe as fantastically complete as the Potterverse, its tempting to try to understand everything about everything, even when that's clearly not possible (particularly if we ever want Jo to finish books 6 & 7, rather than answering fan questions!).

[tarachristwen]

i think magic is somewhat in between. imean some are born into a pure wizarding family and yet they are squibs.some are muggleborn yet they have magical abilities..

[Talio]

This may seem like a half-baked theory, and please, feel free to point out any inconsistencies, but perhaps it's not completely in the genes. When babies are in a mother's womb, what happens to the mother is often carried on to the child in some sense, sometimes amplified. If the mother is magical, obviously the baby will experience magic in the womb and thus there's a high probability of the baby being magical. However, for muggle mothers, this isn't the case. Then how do those babies get the predisoposition for magic? My only theory that stays away from genetics is that, since magical folk do live and sometimes work among muggles, is that a pregnant mother encounters magic of some kind that doesn't effect her, but perhaps has an amplified effect on the fetus.

[drdementor]

GAAAH! After all that work trying to explain Jo's first quote 'Magic is not genetic' we know hear from her that 'Magic is a dominant and resilient gene.' I guess she had more people asking her about genetics, and decided to make it genetic again.

This is not the first time she's changed her mind on a little detail that won't really impact the books (think Hermione's age, first she's the youngest of the trio, then she's the oldest). ;)

Okay, so now we know that magic is genetic and that it is a 'dominant and RESILIENT' gene. This statement makes me think that the usual Mendelian dominance patterns won't apply to magic. Jo said that non-magical children of even one wizarding parent are considered squibs, and squibs are supposed to be extremely rare. This makes me think that there is no genetic penalty for marrying a muggle! When she says magic is a 'resilient' gene, it makes me think that at the cellular level, those gametes containing the 'magic' gene will be preferred to those containing the 'muggle' gene. Perhaps sperm can swim a lot faster, or the eggs are more likely to be the ones sent to the Fallopian tube. Or, maybe it's even on the level of the chromosome. Maybe the 'magic' gene can reproduce itself and eliminate the 'muggle' gene. So the original 'Ww' becomes 'WW' immediately. I doubt we'll ever hear the answer, but if magic is passed on through simple dominance, a lot of the bloodpurists would have validity, because by marrying a half-blood, you'd have a greater chance of having Squib children. No way would Jo let that be the case!

[Leprachaun]

How could magic be genetic? If muggles can bear witchs or wizards then genetics couldn't apply.

[drdementor]

It could apply. Many, many diseases or conditions that people have are caused by mutations that happen spontaneously in their parents' sperm or egg, or in the zygote form. Those are genetic conditions, but the parents don't have those genes at all. Magic would be a much more pleasant result of a genetic mutation, though, wouldn't you agree?

[Leprachaun]

Yes, but don't most mutations cause death. Correct me if I'm wrong. I'm in biology this year and I seem to remember my teacher mentioning that 99.9% of all mutations that occur cause death. I'm not sure though.

[haha]

Yes, but don't most mutations cause death. Correct me if I'm wrong. I'm in biology this year and I seem to remember my teacher mentioning that 99.9% of all mutations that occur cause death. I'm not sure though.

REALLY!! the percentage seems a bit high. I know that some mutations lead to cancer and things like that but isn't moles and things due to mutations? I agree that mutations can cause death but i'm not sure if the percentage is that high. ALthough, my word doen't count for much since i don't do biology :) just having a random guess.

[Leprachaun]

I can't remember if my teacher said death occurred from mutations that happened before birth or after birth.

I may just have imagined him saying these things, because I was on medication for bronchitis when we went over this. The medicine made me drowsy and gave me a short attention-span.

[drdementor]

Well, lots of mutations cause death, I guess, but there are so many conditions caused by simple mutations. Here are the main ones I remember that result in a dominant condition:

*albinism
*dwarfism

Two parents who have no family history of either albinism or dwarfism can have a child that, through a genetic mutation, will lack the ability to produce skin pigment or who will be shorter than most people. That child then will grow up and have a fifty percent chance of passing on that condition to his or her children, if he or she marries a person without that condition.

Most mutations are actually meaningless, or 'silent' mutations, because they occur in non-coding regions.

Probably your professor was speaking in terms of 'macro-evolution,' saying that most mutations resulting in actual phenotype changes are harmful, but that some may have advantages in natural selection and lead to species change.

[Leprachaun]

Probably your professor was speaking in terms of 'macro-evolution,' saying that most mutations resulting in actual phenotype changes are harmful, but that some may have advantages in natural selection and lead to species change.

Yes, we were talking about natural/artificial selection the same week we discussed mutations so that must be what he was talking about.

[Manwë]

I like Ikuko's theory.
But if JK said it was not DNA when it looks like it's DNA and the obvious logic tells you it's DNA, then it surely isn't DNA and we'll discover later what it is about.

[angelzrfree]

If magic were genetic meaning came from your parents then Hermione's parents should be witch's and wizards which doesn't add up.

[drdementor]

Okay, whoop, here we go, a quick genetics lesson:

Genetics means involved with the genes. Jo has now said 'magic is a dominant and resilient gene.'

'Genes' are the coding portions of your DNA. Most DNA is just filler, and has no apparent coding function.

'Coding' means that the genes are used to make proteins. The genes are read by chemicals in your cells, and proteins are assembled amino acid by amino acid based on what the 'genetic code' says.

The code is read by triplets of bases. The 'bases' are the nucleotides Adenine,Guanine,Cytosine and Thymine. Depending on the pattern they make in the gene, they make a different protein. A slight change in the pattern can result in a deformed protein that doesn't work as well. Or the protein might work just fine, even with a little change. Some slight changes are so important that they can cause disease in the person who has them. It only takes one specific little change in the gene for hemoglobin to cause sickle cell, a disease in which red blood cells are deformed so they don't move through the veins and arteries as well.

If a parent has a genetic disorder, there's a chance the children will get it too. The chance can be calculated based on what type of disorder it is and on whether the other parent also has the disease.

You get copies of chromosomes (large aggregates of DNA) from each of your parents. Jo has said that magic is 'dominant' meaning that if you have just one copy, from either your mom or your dad, you will be magic.

On to Hermione and muggle-borns. Hermione's parents were not magical, so how could they have had a magical daughter? There was some sort of mutation in one or both parent's DNA that they passed on to Hermione. The mutation didn't happen in the parent's body, but in the sperm or eggs, so only their children would have it.

If you think there's no way parents can pass on genes that they don't have throughout their body, think again. Dwarfism is a real-life condition that, like 'magic' is caused by a dominant gene. Most little people are born to parents of average size who have no history of little people in their families. About 1 in 10,000 babies, from any parentage, any time, can have dwarfism. People who already have dwarfism can, of course, pass that on to their children (50% chance of passing on the gene if it is the main type of dwarfism and only one parent is a little Person). Just like Hermione will be able to pass on her 'magic gene' to any kids she has.

The really odd thing about 'magic genes' is that it is 'resilient' and I think that means that Hermione has just a good of a chance of having magic kids as Draco does. But it's not odd at all to have kids with a genetic condition different from their parents', grandparents, uncles, aunts, and cousins.

Site about genetics with videos and explanations: http://gslc.genetics.utah.edu/units/basics/

Sites about dwarfism:

http://www.lprf.org/dwarfism.html
http://www.dwarfism.org/

[LeeJordanfan]

There's also the possibility that magic isn't controlled by a single gene. Eye color, for example, is influenced by at least three seperate genes that we know of and geneticists suspect there are others as well. This is why it's possible for brown-eyed people to have blue-eyed children, albeit very rare. This is also why blue-eyed parents can have brown-eyed children. Whatever gene it is, we can infer it most to be carried by the X chromosome, because if they were all Y, females couldn't be magical. Call the magic gene capital "M". But a basic rundown, assuming magic is a single gene wouldn't account for Squibs much, but might look like this:

A very wizard woman (XM, XM), and a wizard man (XM, Y) would always have wizard children.

A very wizard woman (XM,XM) and a muggle man (XY) can mostly likely have these children: Magical girl (XM,X), Magical boy (XM,Y).

A Muggle-born wizard woman like Lily, or half-blood like Tonks, are likely to have the same magical chromosome set, (XM,X). I don't know where Lily would have gotton her M gene, unless sometimes there's a natural mutation of the gene? If a half-blood or muggle sort of woman marries a muggle man (XY) they can have these children: Magical girl (XM,X), Magical Boy (XM,Y), Squib Girl (X,X), Squib Boy (X,Y).

A Muggle-born wizard man (XM,Y) I don't know where he'd get his magic unless its from the mutation possibly mentioned above. Interestingly, this chromosome set is the same as that of a regular wizard man (XM, Y). How's that for intriguing.

But if he married a muggle woman (X,X), they could have these children: Magical Girl (XM, X), Squib Boy (Y,X).

And I mentioned wizard men married to wizard women at the top.

Very rarely, something can happen in genetics where a chromosomes' dominance doesn't come through. This is due to the influence of other genes that influence eye color. This may be the case with magic, it may be influenced by more than one gene, but that gets really complex.

Note on mutations: Most mutations are bad, although a few have been good. It's so rare to find a good one that most geneticists consider mutations bad, as a general rule. Magic may be one of the few good ones.

[buggie]

But I just can't twist it to work with genetics. It's clearly not recessive or dominant. If physics and chemistry can be tossed out, I don't see why genetics should stay in.

In JK Rowling's site under SQUIBS she states that magic is a dominate gene which makes SQUIB very rare. So I conclude that means that magic is not purely generic. Just like muggles can produce wizards, wizards can produce squids.

[ikuko]

Okay, whoop, here we go, a quick genetics lesson:

Genetics means involved with the genes. Jo has now said 'magic is a dominant and resilient gene.'

'Genes' are the coding portions of your DNA. Most DNA is just filler, and has no apparent coding function.

Er... while i agree with most of your post, I would klike to qualify this bit. Gene does not necessarily mean DNA. Gene is an informational sequence coded linearly in organic molecules. It can be DNA, RNA, or some might even argue that proteins contain gene sequences (though the latter can not be as easily read). So, genes might - or might not mean DNA. In fact, you can implant a string of information in the cell using a RNA virus as a carrier (of course, DNA viruses are usually used for this purpose, but still)