I have a theory that both the Mario Bros. and the Wario Bros. are related. To prove this, I will demostrate, on both the account of the Mario Bros. and the Wario Bros., how are they related to what I believe to be the ancestors of the Mario Bros. and the Wario Bros., the two Hylians, Talon and Ingo. Look at the similar traits both in physical and mental conditions, and think about them.
Talon's traits inherited to the Mario/Wario Bros.:
1.really fat(Wario),
2.really muscular arms(Wario)
3.favorite color is red(Mario)
4.tendacy to be lazy(Mario)
5.tendacy to work hard(Wario/Mario)
6.loves chickens(Wario)
7.would like to be rich(Wario)
8.has pointy ears(Wario/Waluigi)
9.has a round nose(Mario/Luigi)
10.has a big nose(Wario/Mario/Luigi)
11.second favorite color is violet blue(Waluigi)
12. has no sideburns because mustache is connected to hair(Wario fits this more closly than his brothers)
13. eyes only have pupils(Wario/Waluigi)
14.likes to wear shirt with sleeves rolled up(Wario)
15.doesn't have a cleft in chin(Mario/Luigi)
16.likes to wear loafers(Mario/Luigi)
17.pupils are big(Mario/Luigi)
18.tendency to sleep if bored(Wario/Mario)
19.would leave if kicked out(Wario)
20.can sleep for a long time(Wario)
21.keeps some money in jars(Wario)
22.has long hair at the back of the head(Wario)
23.has large eyebrows(Wario)
24.Is shorter than Ingo(Wario/Mario)
Ingo's traits inherited to the Mario/Wario Bros.:
1.fat(Wario/Mario),
2.muscular arms(Wario/Mario)
3.favorite color is green(Luigi)
4.tendacy to work hard(Wario/Mario)
5.looks angry all the time(Waluigi)
6.loves to be rich(Wario)
7.has pointy ears(Wario/Waluigi)
8.has a round nose(Mario/Luigi)
9.has a big nose(Wario/Mario/Luigi)
10.has sideburns(Wario/Mario/Waluigi/Luigi))
11.eyes only have pupils(Wario/Waluigi)
12.likes to wear shirt with sleeves rolled up(Wario)
13.doesn't have a cleft in chin(Mario/Luigi)
14.likes to wear pointy shoes(Wario/Waluigi)
15.pupils are big(Mario/Luigi)
16.tendency to be nice if happy(Wario/Mario/Waluigi/Luigi)
17.mustache is pointy and is very smooth(Waluigi/Luigi)
18.eyes have a mean look(Waluigi)
19.sideburns are pointed(Wario/Waluigi)
20.likes to be in charge(Wario/Mario/Waluigi)
21.favorite shoe color is green(Wario)
22.is taller than Talon(Luigi/Waluigi)
No matter how different they look from each other, I say, judging from these similarities, that the Mario Bros. and the Wario Bros. are related in some way through Talon and Ingo. I rest my case.