Does ancestry play a part in magical ability? was: The permanent prob. with Slyt

[Mandy]

No: HPFGUIDX 99374

> Naama wrote:
<snipped a great paragraph>  
> So, to return to your argument, the point is not whether one can 
> change a trait or not, but whether that trait is relevant to the 
> specific field of endeavor. We don't really know whether brains or 
> courage are more important to learning magic, but surely it's clear 
> that ancestry is an arbitrary criterion in this context? This makes 
> Slytherin discriminatory where Gryffindor and Ravenclaw are merely 
> meritocratic. Definitely a very different order of "unfairness."

 
Mandy here:
The question is then; does ancestry play a part in the magical 
ability of children?  It seems as if Jo wants us to think not, how 
else can Hermione be as magically powerful as she is, and Neville be 
a bad as he is.  

But are they the exception to the rule or the norm?  

Do the children of two Magical parents have an advantage? If they do 
then selection based on blood purity has validity and merit. They 
would by nature have greater potential to pass on to their offspring, 
and the rules of natural selection dictates that at least some 
pureblood must remain or the WW would eventually die out.

What canon do we have to support either argument?  Why does the WW 
contain mostly pureblood families if ancestry doesn't play a part?  

Cheers Mandy