[HPforGrownups] Re: Pureblood Vs. Halfblood Vs Fullblood

[Marny Helfrich]

No: HPFGUIDX 106628

Steve/asian_lovr2 said:

>But if a Squib marries a magical person, the >likelihood that they will
> produce non-magical children is extremely thin. You have magical genes
> on both sides of the family, even though, you only have magic on one
> side.

And I (Marny) wonder:

Do we know this from the books, or is this your (very reasonable)
assumption?  We don't know of any Squibs with children from the books,
right?  (It occurs to me, though, that both the known Squibs have cats.  Do
you think there is anything to that?)

Clearly, magic doesn't follow the inheritence patterns of Mendelian
genetics!

This discussion got me thinking about the relative prevelance of folks with
different types of heritage in the books.  I'm adopting Steve's use of
"full-blood" to describe a magical person with two magical parents (rather
than pureblood, which I agree is political and subjective)

So, we have:

full-blood witches and wizards:
Harry, Ron (and all the Weasley sibs), Sirius, James, Neville, Draco, Ernie
Macmillan, Barty Crouch Sr. & Jr.

muggle-born w & w:
Hermione, Lily, Dennis and Collin Creevey, Justin Finch-Fletchly, Penelope
Clearwater (by implication)
note: Ron says "Loads of people come from Muggle Families" (SS, Chapter 6,
The Journey from Platform Nine and 3/4, pg. 100 Scholastic American).

half-and-halfs (one parent a wizard/witch, one a muggle)
Seamus Finnegan, Dean Thomas (per JKR's website, but he doesn't know it),
Tom Riddle, Tonks

Cedric and Luna are both known to have one magical parent, with the other
not specified

mixed-blood (one parent a wizard/witch, one a nonhuman magical creature):
Hargid, Madame Maxime, Fleur delaCoeur

Squibs
Filch, Mrs. Figg, Molly's second cousin the accountant

Unknown (at least to me, but maybe I missed something!):
all the teachers; molly, arthur, Lupin, Peter Pettigrew, Lavender, Parvati,
Cho, Vicktor Crum,

So, by numbers of mentions, it seems like full-bloods predominant in the
Wizarding world, followed by muggle-borns.

The relevance of this, I don't know, but I thought it was somewhat
interesting.

Marny