La evolución consiste basicamente en el cambio de sus rasgos físicos y/o mentales para convertirse en una criatura más poderosa, con nuevas capacidades que deberan ser explotadas por su entrenador. Con esto me refiero fundamentalmente a aquellos Pokémon que al momento de evolucionar adquieren caracteristicas extras a su tipo (Ej: Charizard es fuego y volador), con la que podran aprender nuevos ataques.

La evolución puede ser de distintas formas:

Por sentimientos: Evoluciona de diversos motivos sentimentales: Amor, dolor, ira, etc; por ejemplo en el capitulo en que Charmeleon evoluciona a Charizard para batir a Aerodactyl.
Por piedra: Es la forma de evolución forzosa, en la cual se obliga a la criatura a evolucionar con una piedra especial, sin importar la experiencia. Para los diversos tipos de Pokémon hay diferentes piedras.
Por experiencia: La forma mas común, consiste en que el pokémon, luego de una cantidad de batallas, ya se encuentra en condiciones de evolucionar.
Causas extra: De acuerdo a cada raza de pokemon existen formas alternativas de lograr la evolución. Por ejemplo, en el capitulo de los Magicarps que volvian a su lugar de origen para intentar evolucionar.

**************TIPOS DE EVOLUCIÓN ===================
*** POR ROCAS ***

SOLAR STONE ----> Gloom, Sunkern.
THUNDER STONE --> Pikachu, eevee
WATER STONE ----> Sheldder, staryu, eevee
FIRE STONE -----> growlithe, vulpix, eevee
LEAF STONE -----> gloom, exxecute
MOONSTONE -----> Cleafairy, jigglypuff y a los Nido/ma/he

*** POR FELICIDAD ***
Para hacer feliz a tu pokémon:

- Llévalo a la elite4 + Koga.
- Llévalo a que se corte el pelo en el underground de Goldenrod.
- Haz que la hermana de Gary lo cepille.
- Equípalo con ítems.
- No dejes que se desmaye.

Pokémon que evolucioan de esta manera son chansey, golbat, eevee(en el día, a Espeon, en la noche, a Umbreon)las preevoluciones, entre otros.

*** CAMBIÁNDOLOS ***
Algunos pokémon evolucionan cuando los cambias usando el cable link. Muchos necesitan algún ítem equipado

POKÉMON ÍTEM EVOL
Machoke ---- Machamp.
Seadra dragons scale kingdra
Poliwhirl kings rock politoed
Slowbro kings rock slowking
Onix metal coat Steelix
Scyther metal coat Scizor
Porygon upgrade Porygon2

Pokemon Obtained only by Evolving
==================================
Aggron Evolves from Lairon at level 42
Armaldo Evolves from Anorith at level 40
Azumarill Evolves from Marill at level 18
Beautifly Evolves from Silcoon at level 10
Blaziken Evolves from Combusken at level 36
Breloom Evolves from Shroomish at level 23
Cacturne Evolves from Cacnea at level 32
Camerupt Evolves from Numel at level 33
Combusken Evolves from Torchic at level 16
Cradily Evolves from Lileep at level 40
Crawdaunt Evolves from Corphish at level 30
Donphan Evolves from Phanpy at level 25
Dustox Evolves from Cascoon at level 10
Exploud Evolves from Loudred at level 40
Flygon Evolves from Vibrava at level 45
Gardevoir Evolves from Kirlia at level 30
Glalie Evolves from Snorunt at level 42
Grovyle Evolves from Treecko at level 16
Grumpig Evolves from Spoink at level 32
Kadabra Evolves from Abra at level 16
Kirlia Evolves from Ralts at level 20
Lanturn Evolves from Chinchou at level 27
Machoke Evolves from Machop at level 28
Magcargo Evolves from Slugma at level 38
Marshtomp Evolves from Mudkip at level 16
Masquerain Evolves from Surskit at level 22
Metagross Evolves from Metang at level 45
Metang Evovles from Beldum at level 20
Mightyena Evolves from Poochyena at level 18
Muk Evolves from Grimer at level 38
Ninjack Evolves from Nincada at level 20
Rhydon Evolves from Rhyhorn at level 42
Salammence Evolves from Shelgon at level 50
Sandslash Evolves from Sandshrew at level 22
Sceptile Evolves from Grovyle at level 36
Seadra Evolves from Horsea at level 32
Sealeo Evolves from Spheal at level 32
Shelgon Evolves from Bagon at level 30
Slaking Evolves from Vigoroth at level 36
Swalot Evolves from Gulpin at level 26
Swampert Evovles from Marshtomp at level 36
Vibrava Evolves from Trapinch at level 35
Vigoroth Evolves from Slakoth at level 18
Walrein Evolves from Sealeo at level 44
Weezing Evolves from Koffing at level 35

=============================
Trade induced Evolution
=============================
Alakazam Evolves from Kadabra when Traded
Golem Evolves from Graveler when Traded
Gorebyss Evolves from Clamperl when Traded holding Deepseascale
Huntail Evolves from Clamperl when Traded holding Deepseatooth
Kingdra Evolves from Seadra when Traded holding Dragon Scale
Machamp Evolves from Machoke when Traded

=============================
Hatching in a Egg
=============================
Azurill Hatch from a Egg in Day Care
Igglybuff Hatch from a Egg in Day Care
Pichu Hatch from a Egg in Day Care
Wynaut Hatch from a Egg from Lavaridge Town

=============================
Stone Evolution
=============================
Sun Stone
Gloom into Bellossom

Moon Stone
Skitty into Delcatty
Jigglypuff into Wigglytuff

Water Stone
Lombre into Ludicolo
Staryu into Starmie

Fire Stone
Vulpix into Ninetales

Thunder Stone
Pikachu into Raichu

Leaf Stone
Nuzleaf into Shiftry
Gloom into Vileplume

=============================
In game Trading
=============================
Corsola Trade a Bellossom in Pacifidlog Town
Makuhita Trade a Slakoth in Rustboro City
Skitty Trade a Pikachu in Fortree City

=============================
Friendship Evolution
=============================
Golbat Evolves into Crobat when it really like you.
Pichu Evolves into Pikachu when it really likes you.
Igglybuff Evolves into Jigglypuff when it really likes you.

=============================
High Beauty
=============================
Milotic Evolves from Feebas with High Beauty

Note: To evolve Feebas get to the level you want (preferable 30). Give it 5
level 50 Indigo pokeblocks. To get these blend 5 Pamtre No.32 Berries with the
old man (Mister) at either Normal Rank Hall in Verdanturf Town or Super Rank
Hall in Fallarbor Town. Then raise it one more level and it will Evolve.

=============================
Pokeball Evolution
=============================
Shedinja Evolves from Nincada when Nincada evolves at level 20 you must
have a slot open and a pokeball with you Nincada will evolve into Ninjask
and you will have caught his shed skin which is a pokemon named Shedinja

=======================
Rare JIRACHI & DEOXYS
=======================

Note: Pokemon 201 Jirachi & 202 Deoxys are only available by cheating with the
Action Replay.