Anyone wonder about those Zap Apples?

[Shadechaser]

In season 2 ep 11, not to spoil anypony's fun, but what do you think happened to cause the Zap Apples? We all know that Granny Smith found Zap Apples, but what caused this? Did Granny Smith just happen to come across some unique seeds, or did the Everfree Forest's supernatural essence cause this? (My thoughts: ...Sweetie Belle... those apple trees are charged...) When Sweetie Belle tries to 'buck' the 'Zap Apples' from their tree, she gets shocked, maybe due to the zap attribute of the trees. By the way, who thinks the sound they put for the charge going up, and coming back to shock Sweetie Belle, is cool, or suiting? Anyway, when Granny Smith tells her story, she says she went into the Everfree Forest and found the most amazing Apple Tree. We notice that they look like the Zap Apples, so... what caused the tree to be there? (and / or) is it some supernatural occurrence?

In short,
What do you think caused the Zap Apples to appear in that part of the forest?
When do you think the Zap Apples appeared first?

[Howitzer]

If a 5oz. African swallow beats it's wings at 45 beats per second, and assuming by the mass of the zap apple weights around 1lb., then it might be possible for two African swallows to carry the zap apple by the tusk and combine their airspeed velocity to carry it together when migrating.

[Tiger]

Perhaps Zap Apples are apples that have been modified after being struck by lightning, considering their electrical capabilities.

[GoldenTerrabyte]

There's one line you haven't noted:

Zap apple trees aren't like normal apple trees. They're magic.

So they could've gotten there, I don't know, magically?

[narwhaliagames]

There's one line you haven't noted:

Zap apple trees aren't like normal apple trees. They're magic.

So they could've gotten there, I don't know, magically?

majicz