mendelian genetics

[antoshachekhonte]

No: HPFGUIDX 123704


--- In HPforGrownups at yahoogroups.com, "Alex boyd" <alex51324 at h...> wrote:
> I don't *think* anyone has posted this yet on the genetics "how do squibs 
> happen?" thread, but....
> 
> It's important to remember that complex traits are typically governed by 
> more than one gene.  It's not even clear (to the best of my knowledge)  that 
> eye color (the example usually used in biology textbooks)  is governed only 
> by one gene.  So if being a wizard or not is genetically determined (and 
> maybe it isn't), it's probably determined by lots of genes.  And maybe a 
> person has to have a certain number of W's (to use the notation established 
> earlier in the thread)  to manifest the wizard trait.
> 
> And, given that muggle-born wizards are much more common than Squibs 
> (according to Ron, anyway), I'd say the Wizard gene (or genes) is probably 
> dominant.
> 
> Alex

Antosha:

You know, Celaria (I don't know if she's on HPfGU) pointed out to a few of us that, if the 'W' 
gene is truly dominant, (and if there is just one gene) then there could be no such thing as 
Muggle-born magic-users, since, if the gene was present in either parent, the trait would 
have manifested.

Of course, she then wrote a lovely fic that explored just how Hermione's discovery of this 
very fact blew her family apart. :-)

In any case, we theorized that 'W' is a linked gene--like green eyes or red hair. Which 
would explain why it seems to manifest more strongly in some (ie Harry, Tom Riddle or 
Dumbledore) than in others (ie, Neville, Umbridge or Sybill Trelawney).