One thing that is indisputable in canon, according to every piece of information we have ever been given on the subject, is the fact that the ability to conduct Magical energy is an inherited trait, passed down from parent to child. Beyond that, until the end of 2004, the mechanics of such inheritance were left unspecified.

In her website update of December 10, 2004, however, Ms Rowling threw us a curve. In this update she handed us a statement which if applied to any known scientific principal of Real World genetics would appear to contradict any possibility that any Muggle-born magical children could ever be born at all; let alone comprising one quarter of an average Hogwarts year’s enrollment.

It is impossible at this point to determine whether Ms Rowling actually meant, what she said, in the way she said it or not. The fact that she seems to have reversed her statement in one of her post-DHs interviews would tend to suggest not.

The Potterverse is not our world. And clearly it has some additional elements in play in it, apart from and beyond the fact that in our world there are apparently no active genes for expressing Magic. For that matter, we do not know for an absolute certainty that the inheritance of Magic in the Potterverse is accomplished through the medium of purely physical genes of a sort which might one day be identifiable and cataloged in some Potterverse equivalent to the ongoing Human Genome Project.

Although Ms Rowling does imply this in her statements, it’s unknown to what degree she is simplifying her statements for the benefit of her younger readers.

Which introduces a considerable hurdle of discontinuity into the equation, for the ever-continuing inconvenience of fan theorists. Many of us older fans tend to loose sight of the fact that Ms Rowling has to keep a grasp on the fact that she is required always to explain things in a manner which is accesssible to 9-year-olds. But since her statements, as they were stated, do not hold together with either established scientific fact, or with what she has already shown us in the books, we are forced to consider that either something has been simplified beyond the range of accuracy, or there is some as yet undiscovered (and perhaps undiscoverable) influence present in the patterns of inheritance of both physical and psychic traits in the Potterverse which determines the inheritance of Magic. Possibly some element that is transmitted along with the parents’ physical DNA but is not actually a visible component of it.

In the interim, however, we have to assume that the transmission of one’s own Magical traits to one’s children takes place in a manner that is roughly equivalent to that of the genetic transmission of physical traits, and operates in a manner sufficiently similar to the transmission of physical genes to be explored by the same methods.

Consequently let’s take a look at a basic model before we start extrapolating variations from it. Keep in mind the fact that I am no more a professional geneticist than JK Rowling.

Basic Genetic Theory (Mundane Style, much, much simplified):

Our current understanding of the inheritance of physical traits is that it is dependent upon those microscopic fragments of DNA which form the genes which combine to form the chromosomes which exist in the nucleus of every living cell.

These chromosomes provide the code that forms the template that the body follows in reproducing each individual cell as it dies off and is replaced with a new one. With magnification, science has identified various recognizable examples of genes according to their position in the chromosomes, and can determine something of their behavior in the manner of their interaction with each other.

The Real World human genome consists of 23 pairs of chromosomes each of which contains dozens of genes. Since the chromosomes come in pairs, the individual genes on a chromosome are each characteristically “paired” with a counterpart in the “partner” chromosome which occupies the same position that it occupies in the “chain”. These paired genes interact to produce the instructions as to what qualities are to be exhibited by each newly-produced cel.

The basic forms of interactive behavior between these pairs of genes are:

Dominant, in which one gene, if present, will always override the building instructions of its partner;

Recessive, which allows its instructions to be overridden, but when paired with a gene whose instructions matches its own will execute those instructions, and;

Multifactoral, in which both genes contribute their instructions to the final result, which is a combination of, or a compromise between, the two.

Probably the most familiar example for demonstrating all three types of gene behavior in action is the standard illustration of the inheritance of the four basic human blood types.

The four basic human blood types are; Type A, Type B, Type AB and Type O.

If a gene for Type A, which is classified as Dominent, is paired with a gene for Type O, which is Recessive, the subject will be born with Type A blood. The Dominent Type A gene has overridden the instructions of the Recessive Type O gene.

The same is true with the gene for Type B. If paired with the gene for Type O, the Type B gene is Dominant and the subject will be born with Type B blood.

The gene for Type O is Recessive. Only if both of the subject’s genes are for Type O will the subject be born with Type O blood. With two Recessive genes there is no counter to either’s basic instructions.

However; if you put the ordinarily Dominent genes for Type A and Type B together, neither will give way and their behavior is Multifactoral. These subjects will be born with the AB blood type. Neither gene allows its instructions to be overridden, so the result is that both sets of instructions are followed.

Recessive genes are difficult to trace. Short of knowing the family history, or examining the actual genes under a high-power microscope, there will be no indication whether a subject born with blood Type A is carrying two, or only one gene for Type A blood. Consequently the recessive gene for Type O may be passed along for generations without any indication of its presence in any of the people who have inherited it and passed it on.

This is the basic pattern for the principles of gene dominence. There are many additional modifying factors which I have not touched upon.

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In some comparatively rare cases, the question of whether or not a gene becomes active can depend on where it sits on which chromosome. The 23rd pair of chromosomes in the human genome are not always a perfect match. Whereas in females, these two chromosomes are the same length, in males, they are not.

This means that, in males, any gene that is positioned in the portion of the longer chromosome of this pair which does not have a match — because that whole portion of the opposite chromosome is missing — may activate independently. Such genes activate independently because there is no partner gene to contradict its instructions. These genes are referred to as being “sex-linked”, because their instructions typically only manifest in subjects of one sex, which is to say, men.

In the popular awareness of sex-linked genes few of such genes are beneficial. Red-green color-blindness is probably the most widely known condition related to a sex-linked gene. While it is theoretically possible for the condition to occur in females, the actual incidence of it doing so is very rare. The overwhelming majority of the people diagnosed with this condition are male. It is theoretically possible that there are magical traits which may also be sex-linked, but we have yet to be told of any. Magical conductivity itself is clearly not sex-linked.

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In addition, there are genes that are spontanious mutations. Some of these are not that uncommon, and are reletively harmless, such as the one in which the subject is born with eyes of two different colors, say, one brown and one blue eye. It is not altgether impossible that the ability to express Magic is a mutation of this type. But I am inclined to doubt it. Such mutations do not usually breed as “true” as the expression of Magic appears to.

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In December 2004, Rowling stated in her website update that Magic is a Dominant gene.

But from what we have observed to date in canon, this simply cannot be the case. What seems to be more likely is that the traits which relate to magical qualities are passed along in the manner of Recessives, but that they interrelate with each other Multifactorily. Or — and far more probably — that wherever a magical gene is located in a chromosome, it is likely to activate independently — as if it were sex-linked — because there is no possible opposing gene to contradict its instructions.

Ms Rowling appears to have either had this pointed out to her, or to have changed heer mind, since in at least one of the flurry of post-DHs interviews, she stated that most Muggle-borns have wizards far back in their ancestry, which would go a very long way toward establishing the “Magical” gene as a Recessive.

But it also seems vanishingly unlikely that the inheritance of magic — as Ms Rowling has shown it in canon — could possibly be dependent upon any one, single gene. Or, for that mater, can be *confined* to a single gene, since we have already been told that there are various magical gifts which are exceedingly rare even among wizards, and yet these gifts are shown or implied to occur within specific families, and passed down by the laws of inheritance just like eye color, or magic itself.

Unless genetic science itself operates in a very different manner in the Potterverse from the way it does in the Real World. To claim, as Rowling once did, that Magic is a single Dominent gene would rather on the order of claiming that in the Potterverse, the sun sets in the South. (And if by chance it does, then it must do so for Muggles as well as for wizards.)

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Before continuing, I am going to digress into some additional background material: first, I would like to repeat the definition of what I mean when I refer to “Magic”.

I base my interpretation of Magic upon the premise that Magic (which is to say, raw, “wild” magic) is a form of energy. It is a non-sentient force, such as electricity, and that in the Potterverse some minerals, plants, species, and individuals within specific species are natural conductors of this energy. And that to be such a conductor is to be “magical”.

I extend this interpretation to include the reading that most things on either the material or spiritual “planes” are subject to being affected by Magic when these magical energies are properly focused and directed, but that only those natural conductors are able to constrain this energy into a deliberate form, or to direct it to a specific end. This may be done either consciously, or otherwise.

It should also be noted that the effective methods of focusing or directing the force of magical energy in the manner necessary to affect some things on either plane might not yet have been developed, and that, consequently, to affect them may be currently believed to be impossible.

The primary quality that is shared by all magical species, either beast, being or spirit is that they are all psychically “active”. I am going to try to limit my focus to human magic. Human beings, in the main, are not a magical species. I suspect that human magic has developed along somewhat different routes and, upon the whole, over a later period than the magic of most other sentient magical species, or “Beings”.

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A second issue which needs some background is that of the social interactions within the wizarding world as it relates to human magic:

Once again, I will invoke the background material that Ms. Rowling shared with her fans on national television a few years ago. In these notes it was charted that the population of the wizarding world, at the end of the 20th century, stood at approximately 25% Muggle-born witches and wizards, 50% halfbloods, and 25% purebloods. In addition, I would like to direct your attention to the statement made by Arthur Weasley at some pointbefore the series opened, and quoted by his youngest son early in PS/SS that “We would have died out if we hadn’t married Muggles.” I very much doubt that this statement was made available to us by accident.

So. In the first place; we do not know exactly how long it has taken for the population demographics of the wizarding world to reach their current levels. (Although this issue is explored more throughly in a couple of companion essays.) Nor do we know for certain how many generations decent from a family founder’s original Muggle-born origins are necessary before the generality of wizarding society stops regarding his descendents as halfbloods.

In the case of the diehard pureblood isolationists, all eternity might not be long enough, but the rest of wizarding society is likely to have somewhat laxer standards.

We have also been given no information that would either support nor contradict the question of whether Muggle-born magical children have or have not been steadily assimilated into the wizarding world throughout the entire period that the wizarding world has lived in Seclusion, or if there may have been an early period during which this practice had been temporarily interrupted.

The historic background we have been given strongly implies that until the period immediately preceding the formal establishment of wizarding Seclusion late in the 17th century, wizards and Muggles lived side-by-side and interacted with each other as part of the same culture. This had been the case throughout all of human history to that point. Under such a system it would have been far less likely for anyone outside of a certain very narrow social circle to have expended any great degree of soul-searching over whose great-grandparents might or might not have been magical, so long as his or her children were. Or were not, as the case may be.

I have based all of my conjectures regarding the social history of the Potterverse upon the premise that with the passing of the International Act of Wizarding Secrecy in 1692, the entire wizarding world formally severed contact with mundane society, and removed itself from it, and retiring, as much as possible, behind a “firewall” consisting of Muggle-repelling spells, unplotability, illusions and the prototypes of such portals as those operated manually in the Leaky Cauldron or automatically on Platform 9 3/4. At the very least, wizarding families packed up and moved their households to some other district where their magical abilities were unknown, and ceased to allow themselves to be identified as wizards.

The only Muggles still to know of this secret, magical “world” at that point were those Muggle husbands, wives, parents, siblings, and offspring who chose to accompany the wizards into their new sanctuaries. All others who could be traced were probably Obliviated before the wizards left. The early Ministry of Magic would have also taken steps to limit the likelihood of Muggles encountering wizards — as wizards — in the future, either by accident or design.

In DHs we get a somewhat confusing hint of this, with the passing mention of a handful of traditional, partially-wizarding communities which wizards had gravitated to for mutual protection and support. In a few of these, such as Godric’s Hollow, wizards had already been known to occur over several preceeding centuries, so one really wonders how wizarding secrecy could have possibly been maintained under circumstances wherein the neighboring Muggles were aware that some of their neighbors had peculiar abilities. Presumably, Obliviate was used with a lavish hand.

Under such conditions it would have been very difficult for any Muggle-born magical child outside the known wizardng, or partially-wizarding enclaves to have been noted or identified. Ergo; while the articles of the International Act of Wizarding Secrecy would no doubt have allowed for the continued recruitment of Muggle-born magical children into the wizarding world, even after Seclusion was formally established, the actual incidence of such recruitments gradually became exceedingly rare. Since at the time of the establishment of statuatory Seclusion the Muggle population of Great Britain might have produced no more than one Muggle-born magical child in an average year this is hardly to be wondered at.

My premise further postulates that at some point, about a century after the staruatory adoption of Seclusion, it was becoming apparent to those who were in a position to oversee the wizarding world’s welfare, that its population’s birthrate was insufficient to maintain its numbers at a high enough level either to survive over the long term, or, in the shorter term, to retain its current position of dominance in the power balance vis-a-vis the other partcipating species of the magical Brotherhood. In addition, a discernable rise in the number of magical children being born outside the wizarding world was reaching the point that they were becoming a security risk. You can only foster the belief among Muggles that magic does not exist if there are no wizards practicing magic out in mundane view. Unintentionally or not, these children were practicing magic.

I postulate that it was ultimately decided among the wizarding world’s leaders to make a virtue of necessity and to take aggressive steps to identify, train and assimilate these Muggle-born magical children into the wizarding world, both from a security standpoint by removing them from the general view of Muggles, as well as to lay a claim upon these children’s talents to offset natural attrition, and to increase their own work force.

It would have been at this point that a cross-section of the secluded population, who had nothing but bad associations with Muggles — dating from the era that Seclusion had been determined to be necessary for wizards’ continued survival — would have begun to put a renewed emphasis upon the need to distinguish those who were descended from sound, old, pureblooded wizarding ancestry, from anyone who was an interloping mudblood. I postulate that this particular point in time was most likely to have been early in the first half of the 19th century. The wizarding world has been dealing with the ramifications of this situation and the response to it ever since. With varying degrees of success.

(A reasonable argument can be made that this inclusive policy may have been adopted anything up to a century later, but this view is difficult to reconcile with the current population demographics. It takes time for an annual intake of 2-10 people to become established as a quarter of the whole population.)

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Which pitches any exploration on the inheritance of magical conductivity into an arguement of semantics.

For one thing: I believe that while the terms halfblood and pureblood were probably in use long before the establishment of Seclusion, I doubt that the term “Muggle-born” is of any such long-established coinage. That term has, to my ear, the ring of the same sort of Victorian euphemism that rechristened the breast of a fowl as the “white meat”. Regrettably, I suspect that the original, pre-Seclusion term was probably our old un-friend, “mudblood”. A term, which, while certainly no compliment, at that point, may not yet have acquired all of the pejorative implications that it carries today. In a coarser age, it was probably no more negative a term than that of “native”. Although, admittedly, it had probably also been no less so.

On the other hand, for all we know, at that period the term “mudblood” may not only have been every bit as pejoritive, but it may have carried a very different implication altogether. Given the probable odds in such matters, traditionally such children were a good deal less likely to be the unantcipated magical offspring of two blameless Muggle parents than they were to be unacknowledged halfbloods whose true paternity was unknown; raising serious questions and issues of consangunity once the child had been absorbed into the magical community. To designate a child a mudblood may well have been just another way of calling it a bastard. Or, as such children were referred to by Muggles, “base-born”.

The real objection in such cases was not to the open matter of the child’s apparantly Muggle birth, but to that of it’s shrouded magical ancestry. The application of the slur to today’s legitimately Muggle-born magical children is due to these later-day magical children’s unknown magical ancestry being untracable.

For that matter, the term “halfblood” seems to have also undergone a shift in meaning since the establishment of Seclusion. Whereas, at the time the seclusion of the wizarding world was imposed, the term may well have been applied primarily to those persons who actually were the children of a mixed marriage (or some other, more irregular connection where paternity was acknowledged), we have already seen that this term is far more broadly applied in modern day. The presumed need to maintain a distinction between purebloods and everyone else has resulted in the designation of halfblood now being applied to children with as little as one Muggle-born parent, grandparent or, quite probably, great-grandparent or beyond. Even though all of the child’s recent antecedents are, in fact, magical.

It is at present unclear in canon as to just how many generations of functioning magic are necessary to cancel out the “taint” of Muggledom in the eyes of general wizarding society — which is not even the standard of the most rigid of sticklers, like those which are still upheld by blood-purity fanatics on the order of the late Madam Black.

It is also uncertain what the percentage of such technical halfbloods as opposed to literal halfbloods goes towards making up that 50% of the current wizarding world’s population which is referenced in Rowling’s notes. My own suspicion is that it accounts for most of them; since the continuing practice of at least statuatory Seclusion considerably limits the opportunities for such attachments which result in literal halfbloods.

Which reminds us: we know of no instance in canon wherein a witch or wizard married, or became otherwise involved with a Muggle in which the Muggle was informed of the truth of the matter ahead of time. This has not, in general, contributed to long-lasting mixed marriages with multiple children.

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But, returning to the question of the inheritance of Magic:

Keeping all of these distinctions in the back of our minds, we will first deal with the unambiguous and the inarguable; the statement made that 25% of the current wizarding world (or at least 25% of a Hogwarts year’s average enrollment) is Muggle-born.

The magical conductivity of Muggle-born wizards has to come from somewhere. Rowling stated on her website that magic is a “dominant and resilient gene”. The problem with Dominant genes, however, is that they are not resiliant. Once a Dominant gene fails to be passed on, it’s gone. It does not skip generations. It is either there, and active, or it is completely out of the equation. Unless Ms Rowling defines magical conductivity as a spontaneous mutation which occurs regularly in about 0.005% of the mundane births wthin the Hogwarts Quill’s sensory range, Muggle-born wizards cannot be the result of a Dominant gene that is not present in their parents’ DNA.

Admittendly, I am not a geneticist; and so I cannot tell you whether there is any mutation which occurs in a consistent and recognizable form at this level of regularity to serve as an appropriate parallel (there may be one, possibly more than one). But I find it difficult, even impossible, to suspend my disbelief far enough to accept that the “exact same” recognizable mutation can spontaniously occur at such a rate that one quarter of the wizarding population carries it, in even such a complete AU as the Potterverse. If this is the case, Petunia Dursley is right. They are freaks.

Nor does the human race naturally select to magical conductivity. Humans are not an inherently magical species. Magical conductivity is an abberation in humans. So what we are getting in the occurance of Muggle-borns is not something like the way that brown-eyed children occasionally do crop up in blue-eyed families despite the theoretical impossibility of this taking place. In the case of the brown-eyed child, the child’s genome appears to have re-set itself to the basic human template of brown eyes, overriding an established Recessive. But, even then, you will note that such children freqently manage to produce blue-eyed offspring themselves. The Recessive trait clearly is still there.

Rowling’s more recent statement would support the reading that Magical conductivity is, indeed, a Recessive trait. This is at least easier to believe.

However, neither can any “single gene” theory adequately explain the broad range of various levels of magical ability displayed throughout the Potterverse, or the existence of those rare gifts which have been noted in the story to date. One size quite clearly does not fit all.

And given that wizards, in canon, are also cross-fertile with other magical species, *as well as* with non-magical humans, how does one account for the inheritance of non-human magical abilities (which has also been demonstrated in canon) within a “single Dominant gene” model of magical inheritance?

You can’t. I’m not even going to try.

Of course, not everyone agrees with me. And there is no guarantee that I am right. The following breakdown was posted in a debate on A.J. Hall’s (deleted, and much missed) Lj by a Lj user who goes by the name of jehnt. Jehnt takes Rowling’s single gene theory and extrapolates from it, adding the adjustment that the “Squib” gene is a legitimate gene on its own. By taking Rowling at her word that the gene for Magic is Dominant, one is forced to introduce the factor of spontanious mutation to the equation. It should also be noted that while the gene for Magic is stated as being Dominant, the gene for non-magical Muggle appears to be even more so.

Regarding Magic and Society:

Another element contributing to the rise in the number of magical children being born outside the wizarding world is the underlying truism that a rising tide lifts all boats. It is only to be expected that as the overall number of births in the general population rises, more magical children will also be born, even if the rise in their numbers is statistically insignificant when compared against the total number of mundane births.

According to Strauss & Howe, whose theories regarding the rhythms of cyclical history would certainly apply to the ins and outs of mundane history in the Potterverse, cyclical history is punctuated by “great events”, which, once resolved, tend to lead into periods of relative peace, prosperity, and population explosions. Strauss & Howe identify these periods as the “First Turnings” of a 4-part cycle.

The earliest of these First Turnings which S & H have identified covered the period of the rule of Henry VII and continued into the first part of that of Henry VIII. The second of these, initiating the next cycle, took place over the reigns of Elizabeth (late) and James I. A third started with the reign of Queen Anne and continued into the beginnings of the Hanoverian rule. [Note: after, but very soon after formal wizarding Seclusion was established.] In each of these, and in all subsequent “First Turnings” the general population numbers would have surged. Another characteristic of the First Turning is an expansion of the middle classes and an overall improvement in the quality of life of the general population.

It stands to reason that during each of these periods there would have been a larger number of Muggle-born wizards produced, but it would have only been with the lowering of the rates of infant mortality that took place over the 19th century that this factor would have become readily apparent, and increasingly significant.

Once wizarding Seclusion was established, however, these Muggle-born wizards were no longer being identified, taken under wizarding patronage and diverted into the wizarding community. Consequently, any that managed to survive to produce offspring of their own would have been contributing a fully-operative set of wizarding traits to the local mundane gene pool. Which was already fairly rich in them or it would not have managed to produce that Muggle-born wizard in the first place. I suggest that in Rowling’s Potterverse, magical traits are fairly widely dispersed throughout the mundane population of the UK and Ireland. That, in fact, as much as half of the mundane population may be carrying anything up to 1 or 2 magical traits.

In addition, every Squib that has ever left the wizarding community to make his fortune among the Muggles has also contributed an incomplete set of wizarding traits to the general population. Every young wizard out sowing wild oats among the barmaids, every non-magical (apparantly Muggle) near miss, has seeded the available breeding population with magical traits. Ever since wizards began. And, as I say, once the infant mortality rate began dropping in the 19th century, ever more of these carriers have been surviving to reproduce.

And even more to the point, ever since the Acts of Enclosure started forcing thousands of rural families off the land and into the towns and factories, all of these groups of people who might share the same incomplete set of magical traits with everyone in a ten mile radius of their home village had a vastly higher chance of meeting up and pairing off with someone from a different region who may be carrying the missing components to complete that set.

It is also possible that by the mid-19th century the general population level and the wizarding [genetic or otherwise] material within it may have reached the critical levels necessary to start producing Muggle-born wizards on a comparatively regular basis in any case. Wizarding traits have been being recycled back into the gene pool for millennia, and Britain is, after all, an island nation. Its population has been inter-breeding from time immemorial, and if the indigenous folk mythologies of Great Britain can be trusted, wizards were never all THAT uncommon among the Celtic or Pictish tribes prior to the Saxon and Norse invasions. Nor were they unknown among the Saxons and the Normans, either, although rather less common.

Although these traits would have initally been submerged through dilution from successive waves of largely non-magical invaders (or, at any rate more magically-intolerant invaders), if these traits behaved as Recessives, very few of them were actually lost. By the late-18th century they may have finally perpetuated to the point that they were beginning to reestablish themselves within the mundane population of Great Britain.

With the continuing overall rise of the population over the 19th and 20th centuies, the result has been that the births of Muggle-born wizards are steadily becoming more common. The Malfoy/Black et. als. faction actually has some grounds for feeling themselves under siege.

I postulate that there are at least a dozen or so different classes of basic magical traits, and possibly up to couple of hundred minor variations within these basic classes; and that an individual must inherit a minimum number of them (say, somewhere between 6-8) before the subject will be psychically active enough to be capable of conducting Magic.

What is more, any individual subject might carry a LOT more than the minimum. Which would go a long way towards explaining how some wizard/Muggle crosses consistently produce magical offspring while some others may not.

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Which brings us to the examination of the final category in the Muggle-to-magical continuum. I am referring, of course, to Squibs. Squibs are identified in canon as the non-magical offspring of magical parents.

It is at least somewhat evident to the reader that Squibs cannot be absolutely interchangable with Muggles.

If the Potterverse is truly parallel to our own world, then the average Muggle can be expected to be completely unaware of the presence of ghosts. They should certainly be unable to interact with them. And they are stated as being even less able to see or interact with other varieties of spirits which are not ghosts, such as, for example, poltergeists. Or Dementors.

Argus Filch, the caretaker of Hogwarts Academy, has been identified as a Squib. But, whereas the typical Muggle should be unaware of any entity native to the spirit plane, Filch has no difficulty seeing and communicating with the Hogwarts ghosts. He also clearly has an ongoning two-way relationship with the Castle poltergeist, Peeves.

However; Ms Rowling also states on her website that Arabella Figg lied when she claimed that Squibs can see Dementors. Given what Rowling had already established regarding the psychic abilities of Squibs in canon, in the case of Mr Filch, this initally seems to be a bit of poor judgement on Ms Rowling’s part. But in fact it may well be an indication that one size does not fit all Squibs any more than it fits all wizards. Mr Filch is, demonstrably psychically active to at least some degree, regardless of whether Mrs Figg shares this quality. But no Squib is able to actually conduct magical energies. Although, in her website update of December 10, 2004, Rowling does imply that Squibs are able to activate and control previously charmed implements. (If they are not, then Filch is confiscating items that he cannot control or deactivate.)

Rowling has given us the statement in canon that Squibs are very rare. We have only heard of three Squibs in canon to date. Argus Filch, Arabella Figg, and a connection of the Prewett family who went off to make his fortune among the Muggles. Rowling claims that one of the names blasted off the Black family tapesry was in fact a Squib. But this information is at least technically off-canon. The stated rarity of documented Squibs is quite likely to be something that we can take Rowling’s word on. With the magical genotype being as resiliant as it appears (and that much Rowling has shown us in canon) it would take a considerable screw-up in inheritance for a child of magical parents not to be magical as well.

It is also very likely that “Squib” is another comparatively recent term in the wizarding world. One that has only been adopted since Seclusion was actually established. When one considers that prior to the formal and complete separation of the two worlds, if wizards and Muggles lived in the same communities and frequently intermarried, the non-magical offspring even of two wizarding parents might well have simply been regarded as Muggles, who their parents’ magic had skipped.

Having gone out on an unconfirmed limb, however, I suggest that there may be a more than one reason for the birth of a Squib. It is possible that one or more of the traits that a Squib inherited from one or other parent was somehow disabled; possibly through mutation, perhaps due to parental exposure to some form of magical accident, or some particularly damaging form of curse. Or, conversely, that a Squib’s natural channeling of magical energies is designed to difuse the flow of such energies in the same manner that some juvenile wizards have unconsiously taught themselves to do in order to eliminate any accidental magical “breakthroughs”, leaving them with an insufficient magical reservoir to express a spell.

The simplest explanation of course is that, somehow, one or other of the traits necessary to full magical conductivity simply was not passed on, although both of a Squib’s parents possessed it, or that both parents were very low-powered magicals who somehow did not pass on to him the sufficient minimum number of magical traits to produce magical conductivity.

But the most interesting explanation that I can think of is that in Squibs, we may have the equivalent of those rare brown-eyed children of blue-eyed parents. Let me restate: human beings are not a magical species. These non-magical children’s genomes have somehow re-set themselves to the underlying human template of non-conductivity, overriding the instructions of the established Recessives for conducting magic.

But, if it works the same way as it does with the eye color, the Recessives are still there. A Squib, even when paired with an apparent Muggle would be more likely than not to produce magical offspring, even as those rare brown-eyed children of blue-eyed parents have typically been known to produce blue-eyed children themselves. (And indeed, the Weasly cousin who didn’t make it into the final version of GoF was intended to be the witch daughter of the Prewett family’s Squib cousin and his Muggle wife.)

Which suggests that the common deffination of a Squib may be in need of some slght modification.