Originally Posted by AkamaruChewtoy
You have points, but I disagree that all the clans in Konoha are derived from the Senju. While Konoha was founded due to a peace agreement between the Senju and Uchiha, I would tend to believe that the other clans joined up afterwards. The Aburame, Saritobi, Hyuuga, Inuzaka etc all probably found homes under the Senju/Uchiha alliance to gain a stability to thrive. I feel this to be true because Clans usually form from families as a sign of pride - why would someone spurn the utter greatness of Senju to be known as anything else? Also, the byakugan is thought to descend from eye techs similar to the development of the Sharingan. This couldn't have happened in the brief history of the shinobi villages (what - 4-5 generations?).
But I will submit there is little evidence that it is either way - I just am on the side that it is more likely that clans banded together and potentially interbred rather than the Senju clan splitting many times.
As for the passing on of special "genetic" techniques, here's a question: If an Uchiha has a child with a non-Uchiha, will that child develop Sharingan or not? Do all Uchiha develop the Sharingan? It is a fairly unanswerable question until Kishi gives us a situation to this effect, because as much as we'd like to talk genetics of ninja techniques, there's bare evidence to decide how that would work.
New question - has there ever been a picture of a female sharigan user? I can't think of one off the top of my head. Maybe it's Y-chromosome linked... hmmm...
U are probably right about all clans in Konoha not having some Senju dna. Even children of the everyday citizens could have decided to become shinobi and later formed a clan based on their skills. I can definitely see other clans wanting to be apart of Konoha, considering that Konoha was formed from the strongest 2 clans in their world. I know if I was some random clan, I would rather join the strongest of them in their village if everyone decided to team up into villages. But I can see Senju branching off from their name eventhough Senju was a form of pride because Konoha became their pride overall. As long as they were Konoha citizens, they were "Senju" and their new "pride" could have become what their specific, immediate family was capable of that set them apart form other Senju and other ninja. Part of the reason that Uchiha rebelled and Sasuke wants revenge on all of Konoha is because Uchiha were made to feel like they were not equal in Konoha and that they were inferior and second rate citizens, while Senju became 1 and the same with Konoha.
If Uchiha has a child with a non Uchiha, I think that child could possibly develop Sharingan like Haku developed ice when his father was not of their kekkegenkai clan, but that Uchiha with Sahringan would most likey be a much weaker version than those Uchiha that reproduce with other Uchiha. The first Uchiha had to reproduce with normal ninja until they had enough members that they could safely reproduce with other Uchiha and safely build their numbers. I think I remember reading early on that all Uchiha did get the Sharingan, but I havent seen that link since if I did read that in the manga. It seems that their Sharingan isnt as dominant as the Byakugan.
A female Sharingan user? I think the only picture has been in Madara's flashback of the Uchiha clan when telling Sasuke the story. Im almost sure I remember noticing at least 1 shinobi that looked like a female. http://www.onemanga.com/Naruto/398/18/
The one in the middle could pass for a female and the 1 below "her" to the right, especially in the eyes, and they both have the same hairstyle with the "pony tail" http://www.onemanga.com/Naruto/399/17/
Here, in betwen Itachi's father and the Uchiha on the right (on his left side) u see what is clearly an Uchiha girl's face