Boredom leads to pony head canon · 6:14pm Feb 14th, 2012
All right. Been messing with this and I think it'd be fun to type up a bit of head canon. In trying to outline a family structure idea, I happened upon a question: what are pony genetics like?
Now, there is the easy answer of "because ponies" that pretty much let's you get away with anything except an alicorn foal. However, I thought it best to define a set of rules for it, lest an editor complain. So this is what I developed.
Okay, there are two really important episodes for this purpose: Hearth's Warming Eve and Baby Cakes. Hearth's Warming Eve is pertinent because of the three old tribes it introduces. They are very racist towards each other. So this raised a question: what if they had a foal that wasn't of that race? If we assume races are genetic, with some being recessive, then this is a distinct possibility. (for a fic idea, what do they do with such ponies? Exile? Death? Worse (pegasus born to earth ponies loses wings like Clip in BillyColt's fic The Book of Friendship)?) However, given enough time they could theoretically breed out the non-unicorn/pegasus/earth pony genes. This would create a sort of "pure" race. So, we've established a baseline.
Now, what happened when they created Equestria? Consider Baby Cakes and what Mr. Cake said. His ancestors had mixed marriages. Thus, I logic out that unicorn traits are recessive, along with pegasus traits. This leaves earth pony traits as a form of codominance. However, this is based on a one trait based phenotype. I would expect it to be much more complicated, and I'm horrid at advanced biology. But, I feel the need to explain alicorns. I theorize that it is an extremely rare version of whatever-that-biology-term-is-for-both-being-present.
Anyway, the catch all of the theory. It has been so long since the founding of Equestria that everypony has an ancestry that allows for them to have a foal of (theoretically) any race. Don't try and use this to justify an OC alicorn foal though. That is still not a good idea and stretches canon to the limit.
If you're wondering how he eats and breathes,
And other science facts...
Then repeat to yourself 'It's just a show!
I should really just relax...