Board Thread:Theories and Speculation/@comment-5012682-20150620162706/@comment-734582-20150622100248

UltimaDude wrote: Orrr they just did, just like any other clan has some signature jutsu It could've been Madara, who created a Great Fireball that took dozens of shinobi to counter.

It's likely that a handful of uchiha were known for fire release and it then became a pride thing, then a clan thing.

i think it's safe to say that genetics play a part in the whole nature thing (Each nation named after their most common element) but it's clearly not a dominant method. Besides, considering that Kekkei genkai exist and ARE genetic, it's likely that the genetic inheritance method is much, much more complex than, say, eye color.