Wizarding genetics (recent website comments)

[nrenka]

No: HPFGUIDX 123629


Since this is going around, I thought I would add my own two cents, 
because I think it's a productive two cents and avoids certain 
potholes.

Words frequently have technical as well as general meanings.  When 
JKR says that magic is a "dominant, resilient gene", it ends up very 
messy trying to figure it out if you start drawing genetic cross-
boxes and all that, because dominant genes don't actually work that 
way.

Take it in a less technical sense, and what she is saying makes 
perfect sense.  It is a huge theme that there are *no actual 
physical/ontological/whatever* differences between a Muggleborn, a 
half-blood, and a pureblood. If anything states or hints otherwise, I 
would love to see it. The pureblood ideology thread, IMO, is one of 
the most major themes of the books, but its only actual reality is on 
the cultural level (there are/have been some reasons for worry 
there), but decidedly not on more physically real grounds.

Magic arises by chance in the Muggleborn, but then their children are 
not either more or less likely than the children of purebloods to 
become Squibs.  Once you have someone who has the magic capacity, 
that thing is going to preserve itself. We really don't have too many 
cases of magical exogamy to play with, either. We have Dean Thomas 
who thinks he's Muggleborn but actually isn't (per the website info; 
and note that he is the only magical one, but has a number of half-
brothers and sisters), we have Tom Riddle's parents, we have some 
possibility of Lupin's parents.

I think this reading of the comments makes sense with theme, and 
leaves us not having to worry about details of genetics. :)

-Nora gets ready to go copy some manuscripts