From Bulbapedia, the community-driven Pokémon encyclopedia.
Move Evolution is an aspect of the Pokémon Games SpecialK belives in. It first started when he realised that in the anime Water Pulse looked like Aura Sphere, even though they aren't even the same type. Move evolution works on the basis that two moves may have been the same move, but some Pokémon used it for different purposes, and so the move adapted for the purpose it was used for. For example, a Buizel wanted to catch fish for tea (I belive that animals and Pokémon live in the same world), but his Move was unable to go into water very well. It adapted and became Water Pulse. This Buizel showed his friends, such as Empoleon, how to use it and it spread.
Now for Lucario. Lucario was constantely battling Kangaskhan for food, say, but he could not defeat him because his move was not strong enough. So it adapted into the Powerful aura sphere we know today. He showed his friends Aura Sphere and they learned it.
List of Move Pairs/Trios/Whateveros
Water Pulse - Aura Sphere
Roar - Growl
Thundershock - Thunderbolt - Thunder
Confusion - Psycic - Hypnosis
Selfdestruct - Explosion
Sketch - (ANY "MIMIC" LIKE MOVE")
Return - Frustration
Acupressure - Gravity
Roar Of Time - Spacial Rend - Shadow Force
Fissure - Earthquake
Silver Wind - Razor Wind
Quick Attack/Tackle + Any electric-type move - Volt Tackle
Bite - Crunch - Poison Fang
That is all. If you know of any more say on my talk page PLEASE!