"Blood" vs. genetics in the HP books (Was: Magic genetics)

[justcarol67]

No: HPFGUIDX 146502

--- In HPforGrownups at yahoogroups.com, "Magpie" <belviso at a...> wrote:
>
> 
> > Kelleyaynn:
> > I found it interesting that squibs are more common in pureblood
> > families.
> 
> Magpie;
> 
> Squibs are *not* more common in Pureblood families.  There is no
canon about 
> that.
> 
> -m

Carol responds:
I don't want to make a blanket assertion in case I'm wrong, but I
think Magpie is correct. I'm not aware of any canon indicating that
Squibs are more common in pureblood families than mixed blood
families. (Obviously, Squibs would not occur in all-Muggle families;
the children would either be nonmagical Muggles or Muggleborn witches
or wizards like Hermione and Lily.)

Based on JKR's attempt to answer the genetics question on her website
("the wizarding gene is dominant and resilient"), I'd say that her
knowledge of genetics is on a par with her "maths," weak at best. Most
likely she didn't really think about the question when she worked out
the plot of her books. She merely needed three basic types of witches
and wizards as represented by HRH: Purebloods (Ron), half-bloods with
one Muggleborn or Muggle parent (Harry), and Muggleborns (Hermione).
Interestingly, in SS/PS, only two types exist for the little bigot
Draco: those whose parents are a witch and a wizard and "the other
kind." But JKR probably didn't want to complicate matters at that
early point: The concepts of Squibs and Muggleborns are introduced in
CoS, where her focus is on the Heir of Slytherin seeking out
Muggleborns for the monster to petrify or kill.

While we've encountered quite a few Muggleborns, two of whom we know
to be highly gifted witches, we know of only two real Squibs (plus the
presumed Weasley Squib who chose to become an accountant). Neville's
pureblood family feared that he was a Squib, probably because he
didn't exhibit the usual early signs of magic, and Merope was called a
Squib by her evil and abusive pureblood father, but neither of these
examples is evidence that Squibs *usually* occur in pureblood families
because neither Neville nor Merope is actually a Squib. And we have no
idea of the parentage of Mrs. Figg (whose maiden name we don't know)
or Filch. Obviously at least one and probably both parents of Figgy
and Filch were wizards, but we don't know their blood status. (We do
know from JKR's website that Filch's Kwikspell course never worked.)

While I like the highly informed and ingenious arguments that would
allow both Squibs and Muggleborns to exist if the wizarding gene is
both recessive and part of a complex involving at least one other gene
that determines the level of a wizard's power, I don't think that's
what JKR had in mind (as evidenced by her scientifically inaccurate
response on her website). I think she had in mind that most wizards
have "mixed blood," with even the "purebloods" being not really "pure,
as "purebloods" sometime (often?) marry "half-bloods." As long as the
"half-bloods," like Harry, have a witch and a wizard as parents (one
or the other being a Muggleborn), the "purebloods" can claim, like
Ernie MacMillan, to trace their wizard ancestry back, say, twelve
generations. The Muggle parents of the Muggleborn ancestor simply
don't appear on the genealogical charts. It's only the "other kind,"
the Muggleborns, who are shunned as marriage partners by the more
bigoted "purebloods" like the Malfoys, who fear contamination by the
"Mudbloods." My guess is that they fear that the nonmagical "blood"
will contaminate their offspring and increase the chance of producing
a Squib descendant. 

At any rate, setting aside JKR's rather muddled idea of genetics, we
never hear the terms "gene" or "genetics" spoken by any wizard, not
even Dumbledore. It's always "blood." Interestingly, we hear a similar
 view from, of all people, Aunt Marge, the pure Muggle sister of Uncle
Vernon (Harry's uncle by marriage, who shares none of his "blood").
Aunt Marge not only compares human marriage to dog breeding (in which
champions have to be purebreds), she goes so far as to say that the
mother's "blood" matters more than the father's: "If there's something
wrong with the bitch, there's something wrong with the pup." So she's
implying that something is wrong with Lily's "blood" (she hastily
explains to Petunia that such things can occur even in the best of
families, but still it's the Evans line, not the Dursley line, that
contains the bad "blood"). Ironically, it's Lily's "blood" that,
through Petunia, provides protection to the underage Harry as long as
he can call 4 Privet Drive home. So despite Dumbledore's rejection of
the term "Mudblood" and the "pureblood" prejudice that goes with it,
he still, like most of the wizards we see in the HP books, thinks in
terms of "blood," not genes. Maybe Aunt Marge is wrong about the
mother's blood counting more than the father's (Hagrid, for example,
is more like his gentle wizard father than his giant mother who
abandoned him when he was three: "It's not in their natures" to be
motherly, Hagrid says), but still, the concept of "blood" does seem to
have some validity within the books.

On a sidenote, heredity as we understand it does seem to operate in
terms of physical features and certain talents, such as Harry's skills
at flying and Quidditch that he inherited from James, but just
possibly those skills are in his "blood" rather than in his genes. And
"blood" traits can be acquired through "blood" sacrifice and even
transferred, quite literally through the blood, to other wizards ("I
can touch him now," gloats Voldemort after Harry's blood has helped to
resurrect him.)

All this is to say that I don't think debates on genetics will lead us
anywhere. Like the breeders of racehorses and show dogs, and like the
members of European royal houses who for centuries would marry only
others with "royal blood," the inhabitants of the Potterverse see
magical abilities and magic itself as inherited through the "blood."
For that reason, Muggleborns (who, in our view, *must* have magical
genes) are viewed by wizards who care about bloodlines as interlopers,
nothing more than Muggles who have somehow invaded the WW. Voldemort
himself holds this view, equating the Muggleborn Lily Evans Potter
with his own Muggle father in both CoS (as Diary!Tom) and GoF. Salazar
Slytherin, Lucius Malfoy, and even the twelve-year-old Draco of CoS
want to root them out, not because they carry nonmagical genes (they
clearly neither know nor care about such Muggle concepts) but because
their blood is "dirty"--nonmagical and therefore contaminated (in
their view). If neither parent has wizard "blood," neither does the
child, whether or not he or she can perform magic. A Muggleborn is, in
their view, no better than a Muggle. If we tried to explain magical
inheritance to Draco in terms of dominant or recessive genes, he would
have no idea what we were talking about. He "knows," as Aunt Marge
"knows," that it's all in the "blood."

Please note that I am *not* arguing in favor of "blood" prejudice in
any form or accusing JKR of such prejudice, just trying to grasp how
the concepts of "blood" and "bloodlines" work in the books without
bringing in the alien Muggle concept of genetics.

Carol, who would love to have inherited the magical gene or genes of
her "witch" ancestor, Martha Carrier, but whose "blood" is pure Muggle
by WW standards